source of leak

[tg727]

hi all. im new here, ill try and stick around after i get this figured out lol. i have two separate coolant leaks. one i have figured out, its on the side of the radiator. and the other is more or less in the middle of the engine. wanted to know whats around there that could be the source of the leak. ive attached a couple of pics of the leak.

[CarlaValentine]

I'm going to suggest the rear gasket on the water pump as being a good possibility.

[BodybyFisher]

The side tanks on the radiator are plastic and over time they develop stress cracks and leak under pressure, eventually the leak becomes bad and the radiator needs replacing.

The leak you are showing below the water pump can be a few things

1) the water pump itself, leaking at the seal, not installed correctly, or the body seal leaking

2) the crossover seals are leaking, pretty common with age

3) the by pass hose above is leaking, worth a look

4) the thermostat seal is leaking, not likely

Your oil filter looks to be leaking also, it was probably not installed tight

[tg727]

thanks for the input. ordered some parts. replacing rad, water pump, thermo and some gaskets. hope that fixes the leak

[tg727]

after reading some more. i guess i need a new water pump cover also

i bought the upper and lower gaskets that are supposed to be for the waterpump. but dont think ill need them. correct?

[BodybyFisher]

after reading some more. i guess i need a new water pump cover also

i bought the upper and lower gaskets that are supposed to be for the waterpump. but dont think ill need them. correct?

What happened is that the water pump cover seal design changed, as a result when you replace the seal you need to replace the cover, here are photos of the new cover

Here is the old cover next to the new cover

New Cover with view of seal

New Cover with view of Thermostat Housing

[CarlaValentine]

after reading some more. i guess i need a new water pump cover also

i bought the upper and lower gaskets that are supposed to be for the waterpump. but dont think ill need them. correct?

What happened is that the water pump cover seal design changed, as a result when you replace the seal you need to replace the cover, here are photos of the new cover

Here is the old cover next to the new cover

New Cover with view of seal

New Cover with view of Thermostat

Does his year also require that special water pump removal/installation tool?

[BodybyFisher]

Yes

[Bruce Nunnally]

I have a water pump tool but it is a good idea to call your local auto parts shop and see if they offer a free rental; some do. You put down a deposit to guarantee return of the tool but get the deposit back.

[tg727]

found the socket, is what they call it, at advance auto. they didnt have the rental, so i bought it, will probably return it after the job. will i need to change the upper and lower gaskets when replacing the water pump

[BodybyFisher]

found the socket, is what they call it, at advance auto. they didnt have the rental, so i bought it, will probably return it after the job. will i need to change the upper and lower gaskets when replacing the water pump

You lost me, what upper and lower gaskets are you referring to?

The waterpump has a body seal, and a cover seal and the thermostat has a seal

Are you referring to the crossover seals?

[tg727]

http://contentinfo.autozone.com/znetcs/product-info/en/US/fpr/35658/image/6/

http://contentinfo.autozone.com/znetcs/product-info/en/US/fpr/35656/image/6/

these are the gaskets i bought. guess i should replace them too.

[BodybyFisher]

http://contentinfo.a.../35658/image/6/

http://contentinfo.a.../35656/image/6/

these are the gaskets i bought. guess i should replace them too.

Ok Tony, thanks for the photos. That is a crossover seal, there are four of them. I replaced my crossover seals last year when I dropped my carriage to replace sensors in the transmission. Mine were cracked and leaking, I always smelled coolant until I replaced them. One of our members Kevin (KHE) will agree with me that the crossover is a *smurf* of a job, the lower rear bolt is rough to get at, and if I recall you must remove the front electrical conduit and the PRD21 switch. It was a rough job, I have a thread where I moaned about the job, Ill link you to it.

If I recall, the GM R&R time on it was 7 hours and Id like to meet the man who can do that, Maybe having a lift makes the job easier who knows.

That is not part of the water pump or thermostat job. Cadillac wants about $800 for the job. The next time I do it, I hope to have the engine out. If you decide to do the job, we can help you through the process.. I have a 96 also

[tg727]

we skipped the crossover gaskets and got everything else installed. car wont turn over now. checked grounds and put the battery on the charger for a couple of hours. still nothing. had the batt and alternator replaced 6months ago so i know they are good.

[BodybyFisher]

Explain car wont turn over. Does the engine turn over and it wont start?

Keep in mind that the under hood relay center is in the area, check to see if any of the breakers have been dislodged or corroded. You will find fuses/relays for injectors, fuel pump etc.

Take the cover off and reset all breakers/relays and fuses

[tg727]

car will click once. and thats it, no start. accessories and lights turn on. thinking its the starter. but will check battery connections and fuses again

[BodybyFisher]

car will click once. and thats it, no start. accessories and lights turn on. thinking its the starter. but will check battery connections and fuses again

Check the positive battery cable its two wires sandwidged between a lead (Pb) lug. Clean that connection good.

[tg727]

cleaned all connections and it started up. i got stuck at a red light for a couple minutes and the cars temp went up to 222. but went back down to 199 205ish when i started moving. is that normal, what would cause that

[BodybyFisher]

cleaned all connections and it started up. i got stuck at a red light for a couple minutes and the cars temp went up to 222. but went back down to 199 205ish when i started moving. is that normal, what would cause that

That sounds normal, glad it started

[CarlaValentine]

cleaned all connections and it started up. i got stuck at a red light for a couple minutes and the cars temp went up to 222. but went back down to 199 205ish when i started moving. is that normal, what would cause that

I agree that sounds normal. Northstars run hotter than a lot of other engines. I'm not sure exactly why, but I think it has something to do with the high compression ratio. The first time I saw my temp gauge pass 220 I got worried since any other car I've owned ran at an average of 190 or so. Turns out it was nothing to worry about. The fans don't even kick over to high until it gets to 235 (in my car anyhow, unsure about your year) or if you have the AC on.

Unless you are seeing constant high temps over 230 or so, I wouldn't worry. It's normal for the temp to go up a little when the car is idling since there is no air circulation from the outside to help in cooling it. Those temps may get a little higher in hot weather.

I'm happy for you that you got your car fixed and running well!

[BodybyFisher]

Carla your numbers are a little liberal and your statement about the Northstar running HOTTER than other engines is not true.

First of all, the DIGITAL temp readout, causes TOO much concern and panic. It is NOT buffered as it is exact, its digital of course, an ANALOG gage is buffered, and does not illicit panic responses that we do with the DIGITAL readouts. As much as I like the digital readout its somewhat a bad idea as it panics most owners not used to it. It takes some getting used to by observing it, and it's important NOT to jump to quick conclusions but to observe for norms.

You previously PANIC'd in a prior thread of yours regarding temps and I tried to calm your nerves and you keep repeating extremes that I set. I have since posted info for you directly from the FSM showing cooling fan temps.

The northstar has very specific running temps and within those specific temps its ok, but those specific temps are situational.

I will first say that I NEVER want to see higher than 228 degrees. HOWEVER, that said, there are times that I do see higher than 228 degrees

1) After a long drive on the highway, where the engine is hot, I stop the engine to get gas, start the engine, and see 230, 235, etc... that is NORMAL, engine sitting hot

2) In traffic in the HOT months, the cooling is so good with these engines that you rarely see more than 226 to 228....

3) On the highway at speed depending upon the outside temp you will see from 197 to 205, in the hotter months it will get to 212.

4) In August in 100 degree heat after a 400 mile high speed run, I hit traffic, my cooling system was perfect, and I hit 10 miles of bumper to bumper (Virginia Beach), I hit 230 to 242, and my blood pressure went up also, but once I started moving I dropped quickly to 212 to 217.

I said, IF you see 230 to 240 in the SUMMER months it's OK, ONLY in the situation of traffic, hot outside temps, etc but your cooling system has to be PERFECT, seals, hoses, coolant level, fans, coolant concentration, cap, tank, radiator, etc,

These temps can be affected by altitude and even thermostat calibration.

It is important for our members to understand that these temps are VERY specific to the conditions that the vehicle is driven in. Anotherwords, 217 does not bother me in terms of overheating, but, if I saw 217 at highway speed in 80 degree ouside heat, it would signal a problem to me, and I'd be concerned. On the other hand, if I saw 230 in traffic after a high speed run in summer months, at a light or in traffic, I would not be concerned even if I saw 240 in traffic.

These things are situational not to be taken literal. After a while, you know when something is wrong, but don't get panic's by the digital readout, look at your situation in conjuction with it.

Just as a point of reference, it took me 5 years to stand up and feel comfortable about making definitive statements about the Northstar, I am still reluctant to do so as I learn more about it every day, it has changed so much from 93 to now. I was lucky to have the guru to smack me down when I applied old school thinking to the NS or when I would say things like "it runs HOTTER than other engines" and I got to the point where I just observed and learned. Its hard to give advice on the Northstar platform unless you have owned OBD1, OBD2, ISC, AIR pump, plenum, IAC, coil pack varieties,

[CarlaValentine]

Carla your numbers are a little liberal and your statement about the Northstar running HOTTER than other engines is not true.

First of all, the DIGITAL temp readout, causes TOO much concern and panic. It is NOT buffered as it is exact, its digital of course, an ANALOG gage is buffered, and does not illicit panic responses that we do with the DIGITAL readouts. As much as I like the digital readout its somewhat a bad idea as it panics most owners not used to it. It takes some getting used to, observing and its necessary NOT to come to quick conclusions but to observe norms.

You previously PANIC'd in a prior thread of yours regarding temps and I tried to calm your nerves and you keep repeating extremes that I set. I have since posted info for you directly from the FSM showing temps.

The northstar has very specific running temps and within those specific temps its ok, but those specific temps are situational.

I will first say that I NEVER want to see higher than 228 degrees. HOWEVER, that said, there are times that I do see higher than 228 degrees

1) After a long drive on the highway, where the engine is hot, I stop the engine to get gas, start the engine, and see 230, 235, etc... that is NORMAL, engine sitting hot

2) In traffic in the HOT months, the cooling is so good with these engines that you rarely see more than 226 to 228....

3) On the highway at speed depending upon the outside temp you will see from 197 to 205, in the hotter months it will get to 212.

4) In August in 100 degree heat after a 400 mile high speed run, I hit traffic, my cooling system was perfect, and I hit 10 miles of bumper to bumper (Virginia Beach), I hit 230 to 242, and my blood pressure went up also, but once I started moving I dropped quickly to 212 to 217.

I said, IF you see 230 to 240 in the SUMMER months it's OK, ONLY in the situation of traffic, hot outside temps, etc but your cooling system has to be PERFECT, seals, hoses, coolant level, fans, coolant concentration, cap, tank, radiator, etc, in addition you can not be using an octane that causes knocking.

These temps can be affected by altitude and even thermostat calibration.

It is important for our members to understand that these temps are VERY specific to the conditions that the vehicle is driven in. Anotherwords, 217 does not bother me in terms of overheating, but, if I saw 217 at highway speed in 80 degree ouside heat, it would signal a problem to me, and I'd be concerned. On the other hand, if I saw 230 in traffic after a high speed run at a light or in traffic, I would not be concerned even if I saw 240 in traffic.

These things are situational not to be taken literal. After a while, you know when something is wrong, but don't get panic's by the digital readout, look at your situation in conjuction with it.

Just as a point of reference, it took me 5 years to stand up and feel comfortable about making definitive statements about the Northstar, I am still reluctant to do so as I learn more about it every day, it has changed so much from 93 to now. I was lucky to have the guru to smack me down when I applied old school thinking to the NS or when I would say things like "it runs HOTTER than other engines" and I got to the point where I just observed and learned. Its hard to give advice on the Northstar platform unless you have owned OBD1, OBD2, ISC, AIR pump, plenum, IAC, coil pack varieties,

My sincerest apologies. Perhaps I should have worded things a little differently since I was speaking on a basis judged by my own experiences. Thank you for correcting me.

From my experience with my Northstar compared to other vehicles I have previously owned, the Northstar does APPEAR to run hotter, but as you said, the digital display cannot always be depended on for perfect accuracy.

I have gotten used to the way my car runs, and the temperature displays during various kinds of driving/traffic situations. However, I have only had the car registered and on the road since early October of last year. I am sure when summer gets here and it's driven in hot weather, I may see differences in the engine temperatures as well. I believe that is to be expected of any engine.

In the time I have owned my car the highest temp I have EVER seen on it was 236 or 238, and that was due to my surge tank cap not being on all the way, but as soon as it hit that temp my fans kicked up and the temp then returned to about 210 or so. As a side note, that was in stop-and-go city driving.

When on the highway, it averages between 198-206. After getting off the highway back into slower city driving, it averages around 215.

In plain city driving (no highway at all) it normally doesn't get any higher than 200.

I have taken into consideration that it's winter and it's cold outside, and in the summer the temp display MAY increase a little. Regardless, these numbers are normal to me and to my car, and I don't see a problem with them.

Again, I apologize for portraying my observations as facts. You are right. They are not. They are simply MY OBSERVATIONS from my experience, and so should be portrayed as such.

[BodybyFisher]

I only read the first line. There is no need to apoligize NOR do I want to disuade your enthusiasm.

Just keep in mind that we each have direct experience with the year Northstar that we have worked on or owned. I wish I owned a 93 to 95 Northstar, they are so different and I can not answer direct questions on them, and defer to owners who have direct experience.

Unless you are aware of how much the Northstar and Cadillac has changed over the years, one might assume, as I have many times that they are all the same.

Much of your misconceptions could have been due to my inability to convey ideas to you the first time around on the normal temps, plus there is so much more to understand, like how the digital temp gage creates stress if you watch it and not understand it

The digital gage IS in fact perfectly accurate and rises with the coolant temp and it CAN be depended on. The analog (needle) is a little buffered and you wont see it swing so far and so quickly.

Every spring/summer we start to get coolant temp/overheating questions, so expect that topic to pick up when it gets warm, we see it every year, and then in the fall/winter we get HEATER questions when members are freezing.. LOL...

Again, no need to apoligize, the learning for ALL of us never ends

[tg727]

so now im helping my friend replace his radiator in his deville now. i think we bought the wrong radiator though.

we bought the one with the oil cooler. his radiator doesnt have the same holes as the new one we just bought. so im assuming his original doesnt have the oil cooler feature. can we still use the new one and just plug up the extra holes or do we have to replace it?