Engine overheats and heater blows cold air

[sprinter10]

If going up a hill is a dead giveaway for a head gasket and not only that it might have a slow cooling system that is not up to par then I know of 2 other cars that have a headgasket issue that was fixxed by a rigged wiretie on a ctutch fan. Is it possible that an engine overheats when it is strained, has to rev more rpm and has more of a load on it, Therefor will run harder/hotter. If engine is running hotter and coling system is slow and therefor the engine overheats?

I race dirt cars and know that if I run the car normally on a slick track where you are not loading the engine much and just spinning the tires it can run at 195 for an entire 25 lap race and other days on a tacky track it lugs the car down (Like a hill would) and the engine will run 225+ in a 10 lap heat race. I saw this and put a better radiator fan on it along with a coolant aditive mocool that lowered my temp 20 degrees. I know theres others like 40 below and water wetter that claim to lowwer engine tems even more.

When I did the thermostat I notice a lot of thiick gew inside the system that was like puddy coating the inside of the housing could stuff like this be clogging up the heater core and be the reason for the on and off reason for the car overheating sometimes and other times not? On the same hill, at the same temp, on the same day?

[Cadillac Jim]

A properly functioning Northstar cooling system is truly amazing. It has a high rate of flow reverse-flow system that holds the temperature gauge right at 12 O'Clock under just about all driving conditions. The Touring models (the ones with a T in the three-letter acronym, STS, ETC, DTS, etc.) are designed to run 150mph all day on Z-rated tires, or 125 mph all day, governor limited, on H-rated tires. All of them are designed to hold 115 mph on the Autobahn for long trips. That's why you have a power steering cooler; that's the small oil cooler in front of the A/C condenser, low on the passenger side. The Northstar cooling system is so overdesigned for normal legal driving that it has to be crippled for noticeable overheating to be a problem, with the exception of extensive idling in traffic with bad radiator fans.

You can't fix a blown headgasket problem on a reverse-flow cooling system by shorting the cooling fan switch. The problem is steam pockets from cylinder leakage at the thermostat, so that instead of its usual flutter-dance that keeps the engine at the same temperature all the time it stays closed for a few seconds, resulting in a temperature spike. When the bubble passes, the temperature quickly returns to normal.

[sprinter10]

ok Thank you very much a very explanitory response without and sorry for my ignorance Im surprised I would have no built up preashure in my coolant tank. and the reason for the randomness of it heating up or not could be the thermostat being open or not already before you hit the hill I guess.

[sprinter10]

Thinking about getting past newyears and shoveling some snow and get some money together. Then I will start a new thread of a time-sert build you guys have been a great help and I know will be able to guid me through the build Luckely I can drive a coupld other vehicles for a little bit. I have acess to an engine lift, 40x40 semi heated garage shared with a friends sprint car and brother micro sprint, Car lift, and 2 friends that are mechanics that live close by to help with anything I need. I can't thank you guys enough. After this is fixed and I get a new strut for the RR to fix that code (prob get both rears to be even) Then The car should be good to go. I may have just been in denial about it but I really have just fell in love with this car and wanted everything I can to just have it be fixxed easier then the head gasket.

I have been watching http://caddyinfo.ipbhost.com/index.php?showtopic=34066

and was trying to watch to see what the whole build would end up adding up to with the timeserts, gaskets, seals, bushings etc.

What would everyone say would be a fair high and low estimate? I would want to do everything Reasonable while the engine is out and not cut any corners.

I think it sounds like it would still be well worth it for what I have in it already.

$1000 Original cost

$240 new rear coil pack

$20 for thermostat and misc.

$200 Radiator + trans line

Thats $1,460 sofar

What would you guys do? It has some small exterior issues but I have an 18 year old step sister taking autobody in votech and then going to Lincoln Tech so I can get that stuff fixxed. I think the car finnally done with no issues would still be worth over what it will take to get it there.

[Cadillac Jim]

That is a beautiful car. Before you start the Timesert job, you should be absolutely sure that you do need it. When the problem is just starting, it's not at all obvious. There are several ways to be sure, including but not limited to:

• Have the coolant tested for combustion products. This is also a good way to eliminate the possibility of head leakage. This test will tell you for sure whether or not you have head leakage.
• Smell for coolant in the exhaust. This is easiest if you let the car sit overnight after driving it fully hot and parking it for the night, then start it in the morning for a few seconds and shut it down, then see what the exhaust smells like.
• Smell blowby in the coolant.

Ranger, KHE, and others here are experienced enough, both with Northstars and with people coming to Caddyinfo for answers, to have a very nearly 100% hit rate on diagnoses; they don't speak up until they have enough information to be pretty sure. When these guys say something, it's time to get the coolant tested.

There are a lot of other little things you will want to do as part of a Timesert job to make sure that you don't have another problem with what is basically a new engine. Your list is good, but I would also include a water pump, thermostat, plug wires, and plugs.

[BodybyFisher]

That is a beautiful car for sure, and it looks worth fixing the engine.

Do us a big favor however DO NOT automatically assume that you have a head gasket problem, while you have the overheating running up hills, thereby laboring the engine, that does not automatically equate to a head gasket problem, so be careful.

You need to methodically eliminate anything that can cause overheating.

Your experience on dirt cars, while good experience, does not automatically translate to the Northstar. We have always said that, you kind of need to forget everything you learned with the northstar and 'relearn' everything.

You want to

Check the water pump belt to BE SURE it is not slipping and that the water pump belt tensioner is applying good tension and not allowing the belt to slip. A bad belt will act the same as you are seeing now also

You replaced the radiator so its not a flow problem

You replaced the thermostat so its not a regulation problem

You said the purge line is flowing so its not an air problem

You did say that you had a leak, down by the ac compressor was that fixed?

Have you confirmed the cooling fan operation and made sure they are not intermittant?

When its overheating are they running full speed?, with gusto?

I would definately do a coolant test done to confirm that combustion by products have entered your coolant, this is too big of a job to do if you dont have to, here is the test kit

http://www.napaonlin...1006_0282501448

Based the overheating description in your first post in this thread, I initially thought you had a possible head gasket problem and Ranger immediately saw your symptoms as head gasket symptoms. We try to be positive but, having had a head gasket go south you begin to 'cut to the chase' at times and eliminate the possiblity early on.

I would test the coolant

[JohnnyG]

Yes, Ranger and one other person jumped to the same early conclusion. I thought testing the coolant for exhaust gasses was suggested early on, but with a bad cap on the resevoir, it may have been inconclusive. I would like to add that that "brown goop stuck to the insides of everything" sounds to me to be sealant tab residue or the Bar's Leak equivelent. Since I don't think GM used them in the 2000 M/Y, my guess would be that someone tried them in an attempt to stop a cooling system leak, and maybe an excessive amount. If this is true, the heater core may be partially plugged as well.

[sprinter10]

I had my family over tonight and everyone looking at my car and I found that the return hose that goes to the passenger side of the car has huge air bubbles in it and you can hear it when you sqush the hose and move it up and down you can hear the bubbles move back and forth in the line. Then I started it and could not get the air bubbles to leave the line also was looking at how low the lines are mounted in the radiator with no vent at the top how is it possible to get the air out of the top of the tanks and the radiator? Every time I take off from a stop I hear a good amount of air bubble moving through the heater core. After the engine is cool tomorrow after school I will check the bleeder hose to see if it is still flowing water. I will then call up my friends that are mechanics and see if I can get the coolant tested for combustion gasses.

I know a lot of people mentioned to check the coolant and i mentioned it to my father a few times and he said it was a good Idea to but didn't know how he was going ot go about it since he never did it before he was hesitent and put off going to buy the tester or asking someone if they have it. I am finnally able to now That I have my license and will get back with the results.

Thanks for hanging in there and for all of the help with trying to get this figured out.

I held the hoses as it was running for awhile today and the temp whent up to half way and stayed there for a few minutes before the bottom hose thats on the thermostat got warm form the thermostat finally opening it never went above half way though and the fans never came on. Idk if it suposed to open up a little before the temp gauge gets to 12oclock

[Cadillac Jim]

The kit is a bit pricey for just one use, and they aren't good after about six months. Any good radiator shop and many full-service mechanics can test your coolant for combustion products. Call around the chains, like Sears Auto, Firestone Stores, Pep Boys Service, etc. too.

[sprinter10]

OK I have a guy with a private shop,

a guy at a dodge dealership

and I have been picking all of my parts up from advance auto

I will check with all 3 and at least one of them should be able to.

[Ranger]

I think you can borrow the tester at Autozone on their tool loan program for free, but you'll have to pay for the fluid. I doubt that's very expensive.

[JohnnyG]

I had my family over tonight and everyone looking at my car and I found that the return hose that goes to the passenger side of the car has huge air bubbles in it and you can hear it when you sqush the hose and move it up and down you can hear the bubbles move back and forth in the line. Then I started it and could not get the air bubbles to leave the line also was looking at how low the lines are mounted in the radiator with no vent at the top how is it possible to get the air out of the top of the tanks and the radiator? Every time I take off from a stop I hear a good amount of air bubble moving through the heater core. After the engine is cool tomorrow after school I will check the bleeder hose to see if it is still flowing water.

Mark, as I said in my first post, you have to wonder where this air is coming from. I'm going to suggest that it's not technically "air" but exhaust gasses which are being injected into your cooling system due to a headgasket leak. Now I know, I'm as anxious as everyone else to have you able to solve this issue and it's NOT the headgasket, but things are looking dimmer and dimmer. I also realize that this sounds like an oversimplification of how the headgasket problem eventually shows up. BBF alluded to it in an earlier post, the gasses accumulate over time, then cause issues with things like the water pump losing prime, or the "air" just blocking circulation. (centrifugal pumps, including your water pump on this car will NOT pump air) You've given this issue your best shot and fixed many issues by yourself. Each time I felt that you really found the problem this time. You are to be commended for sticking with this for as long as you have, it really shows how much pride you have in your work! Try to get that air out any way you can, and hopefully it won't come back!

The coolant test most likely checks for the presence of CO in your cooling system, or unburned hydrocarbons, it won't be hard to do, but don't go opening up the system or flushing it out before the test. This might give you a false negative reading.

Oddly enough, I just went out to check my Caddy (2008 DTS) and found that instead of the air bleed line coming off the hollow bolt in the throttle body, it now comes off of a "Y" at he connection of that upper radiator hose as it enters the water pump. Maybe Caddy found a bit of air trapped in there themselves and did a redesign. My upper hose though is on the drivers side of the car, so a lot of things are different.

[sprinter10]

I was just reading on a nother site that there is the fix in the bottle company RX Auto that sells an entire kit just for cadillacs it comes with there gasket in a bottle along with a t fitting and some other instuctions and has you put in a second return purge line then flush the gasket in a bottle through it.

I want apsolutly nothing to do with a gasket in a bottle fix and oviously when the problem would be stripped bolt threads and not even the head gasket. But just looking at the system myself I see that it does not look like it can get all of the air out of the system and man do I have air in the system

When ever I pull away from a red light or even just rev the motor to 1,500-2,500 normall driving I get a crazy amount of air sounds in the coolant and its been like this for days. Before I start the car I have been checking my coolant level to see it is not lowering at all. If there were air in the system that was being purged out then the coolant level would drop because the coolant will get pulled in to take up the space that the air was taking up. I was thinking about finding some big inclines that I can run the car up and down on at random different angles to try and work some of the bubbles out maby having the drivers side higher where the purge line is?

I Didn't know if the accelerating force was the reason for the bubbling sound or not so while I was driving I put the car in N and slowly reved the engine at idel I heard nothing but as I reved it up more and more sloshing gurgling sounds I heard. I called up 2 places today and they didn't have the tester. The guy at advance said it was expensive. I found someone else that sais autozone has it to rent if you buy the fluid So i will do that first thing tomorrow just to get the finall answer. I willl check it cold warm and hot if I can to see if the blue fluid turns yellow I have only added around a few ounces of water today but drove it around 50 miles since and will have a few more before I test it prob be close to 70 or so that should be enough circulation to get rid of the new stuff I put in the tank. I am bringing it to my friend to look at tomorrow to get his ideas on the air bubbles that might be trapped also.

[BodybyFisher]

Do me a BIG favor, remove the "BOLT with a HOLE in it" by the throttle body CAREFULLY. Take off the hose, get a 15 mm wrench and slowly back it out, and look at the metering hole, see if it is clear, and do it NOW.... In the first photo, its the small circle at 2 o'clock

Are you the member who said that your 'bolt with a hole in it' was rounded off?, if you are, you NEED to get that bolt OUT and look at the metering hole to MAKE SURE it is clear.

Here is the "bolt with a hole in it" location

I pulled this piece of silicone gasket material out of someone's metering hole in the bolt with a hole in it

[JohnnyG]

Before I start the car I have been checking my coolant level to see it is not lowering at all. If there were air in the system that was being purged out then the coolant level would drop because the coolant will get pulled in to take up the space that the air was taking up.

I don't think this is exactly how this works, but neither can I tell you exactly how any air accumulated in the tank eventually is expelled. Air or gasses, being highly compressible, may just accumulate until an overheat condition exists, then is forced out of the pressure cap. As some have mentioned, the best chance to smell burning coolant at your tailpipe, is just after you start the car. This may also be evidence that some of that air, as well as some coolant, gets pushed back into the combustion chambers when the engine is turned off. Who knows, if an exhaust or intake valve is open at that time,(on the leaking cylinder) you have a direct vent to the atmosphere.

Stay away from the fix in a bottle, we've had other members try it with no success.

[BodybyFisher]

Also what was the outcome of the leak you had down by the alternator?

[sprinter10]

Took the car on the highway today to get to the closest autozone with the block tester I tried taking roads to avoid highway but got lost so I dialed in the gps and off I went. averaging 70 mph up and down hills never once went over half-way. around 10 miles in each direction. I got home with my rented block tester and fluid and got it going. The block tester leaked the fluid out the bottom so I had to hold my finger over the hole when I squeezed the plunger and then put it on the tank and release. I did this for a minute when it was just hot and steeming up a little then I started the engine quick and continued for another minute. The fluid went from blue to a lightish green blue witch it sais is normal with just the air going through it. I did this 3 times first time did not keep the fluid and the second time to much leaked out and couldn't reallly read the color. I did it a 3rd try and was able to get a good reading. I then took a control and filled it up again, started the motor and went to the eghuast with it turned Yellow in under 30 seconds so the fluid was good.

I will post pictures in a second service stinks and it is taking forever to send the pictures

[BodybyFisher]

What was the result of the bolt with a hole in it test I asked you to perform above, did you do that yet?

I dont know this test, as to how the colors work, does that mean that there is no combustion by products in your coolant? GREEN is OK?

[sprinter10]

These results were without checking the bolt I did this before I got home. I will check the bolt tomorrow

The left was first test fluid looks light because light shine through easy because of lack of fluid

The middle cup was my second test where I was more carful with the fluid doing the test with the vapors steeming up getting sucked into fluid

Right side was sucking the eghaust just to see what yellow looks like.

The back of the box says if not yellow then no gas if it is blue or blue green there are no gasket leaks.

New problem picking up brother on screwy backroads with gps not knowing where to go I was doing k turn after k turn and at the end after idling and my brother getting in the car I lost power steering at idle. as soon as the rpms go up over 650rpm it comes back other then that you are wrenching on the wheel. When I pulled in my driveway I let it idle when I checked the fluid level and it was at the top of the stick.

[BodybyFisher]

Check your serp belt to see if its getting wet next time that happens, that will cause it to slip, didnt you say that you had a leak down by the ac compressor? What was the result of that, did you fix that?

If the belt is not getting wet, check to see if the belt is old, cracking or missing sections or if it looks like it is slipping. Check the tensioner to make sure that it is applying appropriate tension and that it has not frozen up or binded in place. It must apply tension or you will get those types of problems

[sprinter10]

The mechanic I am seeing tomorrow has the better pliers to get in and take off and replace the hose clamp I can not get it with my plyers it dripps a few drips over night when I put a peace of carboard under the car but stops when it is warm and there is bearly a drop in the coolant level so it is just one of those cosmetic drips but I will be fixing it. That is on the left side near the radiator it is not getting the belt wet. It would be possible for the belt to get wet while driving because I have not put the plastic under skid under the front of the car to keep it open to look for leaks and to fix that one clamp. I looked at the belt quick the other day and it did not stick out to me but I will check that tomorrow also.

[Ranger]

Forget the repair in a bottle. It is a temporary band aid at best and may cause more problems if it is a HG and you decide to repair in in the future. Remember, "If it sounds too good to be true, it usually is". They don't call it "Hope in a bottle" for nothing.

Keep in mind that blue & green make yellow. The blue fluid turns green first then goes to yellow. To me, green means only a small amount of exhaust gases are present, not enough to turn it full yellow.......... yet. Now I'm just applying logic here, but to my way of thinking, green is a "red flag" so to speak and warrants keeping a closer eye on it. IF it is a head gasket, the symptoms will only get worse and a subsistence test will eventually turn yellow.

For what it's worth I seem to recall someone once say that Autozones fluid left something to be desired. They did the test and got similar results until they used a fluid from Napa. One other thing to keep in mind is that the surge tank is a very low flow area. If you have topped it off with coolant or water, you dilute the fluid in there and MAY get a false negative reading. You want to do the test right after an overheat situation as that is when there would be the most concentrated amount of exhaust gases in the tank if in fact a HG is leaking.

JohnnyG is right. Your coolant level will only go down when/if the gasket breach is bad enough to push the coolant out the overflow or maybe leak back into a cylinder after shut down a small amount at a time. You may not be there yet, but overheating on a hill climb and air in the cooling system (heater core) are pretty damning symptoms I hate to say.

[sprinter10]

I called up a couple napas they didn't have it (Or they did and didn't know it) iT actually just boiled over with the cap off then I shut it off and checked it as it was still kinda steaming so I got a pretty goot test of It I think.

The repair in a bottle was not what I want I want what comes with there $150 kit witch is a t and a hose that creats a second purge line apearantly to get rid of air bubble better then stock. Witch I beleive northstar did with the new model cars because GM knew there was a problem at times purging the air out. I know I talked to one guy that said that they were notoriouse for this.

[Ranger]

Block test kit.

http://www.amazon.com/Lisle-Combustion-Leak-Detector-75500/dp/B0007ZDRUI

The repair in a bottle was not what I want I want what comes with there $150 kit witch is a t and a hose that creats a second purge line apearantly to get rid of air bubble better then stock. Witch I beleive northstar did with the new model cars because GM knew there was a problem at times purging the air out. I know I talked to one guy that said that they were notoriouse for this.

I think I know what you are talking about. It's just another band aid that will prolong the inevitable if it is a HG. Don't waste your money.

[sprinter10]

Thats pretty much the tester I used but the one I had had a rubber pump with a checkvalve in stead of that long hose.