Northstar Engine

[robjr100]

I have a 1999 Deville with the 4.6 Northstar engine.I bought this car in 2006 with 11,000 miles on it and have enjoyed driving it. This past year I learned about the problems the Northstar has with the head gasket,ect. I now have 68,000 miles on it and am concerned about engine problems. I`ve read where 1999 models were high on the list of problem model years.My neighborhood mechanic seems to think I`ll have engine problems without a doubt by 80,000 miles. The engine runs great.Although I do have to add a quart of oil every few thousand miles. Do any of these engines NOT have problems or can a pretty much count on it?

[rockfangd]

Dont worry for a second.

Change the coolant bi annually and drive it hard. I stand by it.

It is a common problem but Proper maintnence helps greatly.

Welcome to Caddyinfo Forum.

Your neighborhood mechanic has their own opinion . But think about all the ones they have not seen as opposed to the ones they have.

People judge problems because they run into them but never seem to see the other side ( the positive side) so they dont know how good they really are

[James Woods]

You really on read or hear about the cars with problems. For every one that needed a head gasket repair I bet there was 10 that did not. Its just that people come into forums to solve a problem or complain about a problem.

[winterset]

I believe you can go 4 years on the orange coolant, but only 2 if someone changed it to the green. Either way, adding a tube of the gm recommended bars stop leak powder to the upper radiator hose (end near the water pump at every change helps imo) fresh coolant, and keeping the coolant away from the head bolts and gaskets also helps. Most important thing to do is inspect the radiator, surge tank, waterpump, and crossover pipe for leaks or cracks. Address any leak immediately before an internal air pocket forms, and causes an unknown head gasket breech which will cause failure down the road.

[robjr100]

Dont worry for a second.

Change the coolant bi annually and drive it hard. I stand by it.

It is a common problem but Proper maintnence helps greatly.

Welcome to Caddyinfo Forum.

Your neighborhood mechanic has their own opinion . But think about all the ones they have not seen as opposed to the ones they have.

People judge problems because they run into them but never seem to see the other side ( the positive side) so they dont know how good they really are

I do see a fair amount of these late 90s Deville`s on the road.I find it hard to believe that all these cars have had this problem. Thanks for the input.

[Burt V B]

I have a 2000 Deville 73000 mi. Head gasket were fixed @ 66000. However, its using 2 quarts oil every 1000 mi. I've replaced pcv and am at a loss as to why. HELP !!!!!!

[KHE]

I have a 2000 Deville 73000 mi. Head gasket were fixed @ 66000. However, its using 2 quarts oil every 1000 mi. I've replaced pcv and am at a loss as to why. HELP !!!!!!

The piston rings are probably all carboned up and stuck. This was an issue with the pre-2000 Northstars and the pistons and rings were redesigned for the 2000 model year to eliminate the issue.

Put the gear shift lever in "2" and floor it until you hit 70 MPH, then let off the gas and let the engine brake until 45 MPH and then repeat until you do not see any soot coming out of the tail pipes. Many times, the rings can be loosened up with this procedure.

[BodybyFisher]

Burt Kevin posted the best way to dramatically improve oil consumption. When I first got my 96 it sucked oil badly. Doing the procedure detailed above completely eliminated oil consumption. Do it once a week until you seenan improvement. Letting the transmission haul the car down to 45 creates negative backpressure in the combustion chamber blowing out debris and exercising the rings.

Every chance you get open it up getting on to turnpikes, babying this engine is a no no.

Who fixed the head gaskets and did they timesert the block?

[rockfangd]

Thats weird. I have had no major consumption issues with pre 2k but have had issues with 00-02. More than twice the consumption of the 90s era.

I always woot and drive em like I stole em lol

[James Woods]

I never really had bad oil consumption problems either on my press 2000 northstar engines. On my 2002 DTS and 2003 DHS they burn a quart about every 750-1000 miles. I suck about 2 bottles of water through a vacuum line and it helps. Maybe after water treatment I only burn a quart every 2000-2500 miles.

An old timer showed me the method. Slowly suck in water through a small vacuum line at idle. The theory is the water turns to steam in the cylinder and cleans out carbon build up. Can't confirm the theory but can tell you it helps with oil burning.

On my previous 2001 DTS I had a caddilac warranty and they wouldn't replace or repair the engine until consumption was at or more than a quart every 500 miles. Considered normal by Cadillac anything less than that.

[BodybyFisher]

My 96 before I bought it was driven by an old man who bragged about babying it. Wrong... driving it had with frequent WOTs (within reasonable rpm) cured the oil consumption

[BodybyFisher]

I never really had bad oil consumption problems either on my press 2000 northstar engines. On my 2002 DTS and 2003 DHS they burn a quart about every 750-1000 miles. I suck about 2 bottles of water through a vacuum line and it helps. Maybe after water treatment I only burn a quart every 2000-2500 miles.

An old timer showed me the method. Slowly suck in water through a small vacuum line at idle. The theory is the water turns to steam in the cylinder and cleans out carbon build up. Can't confirm the theory but can tell you it helps with oil burning.

On my previous 2001 DTS I had a caddilac warranty and they wouldn't replace or repair the engine until consumption was at or more than a quart every 500 miles. Considered normal by Cadillac anything less than that.

Have you tried the WOT procedure that KHE described above?

[James Woods]

Haven't tried the wot yet. Never knew about it. When oil consumption gets high I'll try that 1st know.

[winterset]

I have a 2000 Deville 73000 mi. Head gasket were fixed @ 66000. However, its using 2 quarts oil every 1000 mi. I've replaced pcv and am at a loss as to why. HELP !!!!!!

besides needing a nice long agressive drive or a few wot procedures, consider that you might be overfilling it, and thus loosing some from blowby into yout intake. Oil should be checked on a hot engine on level ground after it has been off for 5 or 10 minutes.

[robjr100]

What do the Cadillac dealers say about the radiator flush to avoid the head gasket problem? Also what do they say about running the car to 70mph in 2nd gear to help fix oil burning problem?

[winterset]

Cadillac dealers will say to trade in your old cadillac for a new one. I do not know of anyone who would officially tell you to perform a wot. BUT unofficially, besides it being performed by several of us, and mentioned by a auto engineer as being ok. I know the 4t65e transmission can handle it. I myself only accelerate a little heavy to 60, then let the rings dance down to 30 and repeat this 4x. As far as coolant flushes, everyone wants to sell you a flush, but every 4 years, a drain and refill is all that is needed for dexcool. I still follow the obsolete recommendation of addng a tube of bars stop leak powder into the upper radiator hose prior to filling with the new "GM approved coolant"

.

[BodybyFisher]

What do the Cadillac dealers say about the radiator flush to avoid the head gasket problem? Also what do they say about running the car to 70mph in 2nd gear to help fix oil burning problem?

I am not sure how radiator flush would lessen the incidence of head gasket failures. However changing the coolant on schedule would help. Coolant beyond its recommended change schedule becomes acidic. If by radiator flush you mean drain and refill great, we do not advise machine flushes that are out there.

Its not likely that a dealer would recommend the wot procedure for lots of potential liability reasons the greatest of which you need to break the 55 mph speed limit, the potential you may get into an accident etc, its also likely that they would not know about the procedure and would rather sell you a service to attemt to free the rings or an engine job. The wot procedure was handed down to us by one of the engineers of the northstar. It has been modified from its original form. The procedure used to require running the engine up to the red line in second gear which we felt developed too much speed and was hard on the engine as it aged. The red line if I recall was 5800 and 6400 for the etc sts engine give or take. 70 works fine as a margin of safety.

[robjr100]

I found this lengthy thread from 2010 about the WOT procedure.

http://caddyinfo.ipbhost.com/index.php?showtopic=33344

[BodybyFisher]

Yes I remember that. I blamed a WOT for blowi ng my head gasket. Let me say that that WOT went to about 90 well beyond where I drove the engine before I actually abused the engine that day. But I will say this, if it happened that day, it was bound to happen any day at that point, it was a matter of time. A sound Northstar can be driven all day like that. My engine at that point had about 130K.

You can see the push back in that thread I cant say we have ever seen anyone cause engine damage or blown head gasket doing a WOT and if it does happen the engine was on its last leg

[robjr100]

What do the Cadillac dealers say about the radiator flush to avoid the head gasket problem? Also what do they say about running the car to 70mph in 2nd gear to help fix oil burning problem?

I am not sure how radiator flush would lessen the incidence of head gasket failures. However changing the coolant on schedule would help. Coolant beyond its recommended change schedule becomes acidic. If by radiator flush you mean drain and refill great, we do not advise machine flushes that are out there.

Its not likely that a dealer would recommend the wot procedure for lots of potential liability reasons the greatest of which you need to break the 55 mph speed limit, the potential you may get into an accident etc, its also likely that they would not know about the procedure and would rather sell you a service to attemt to free the rings or an engine job. The wot procedure was handed down to us by one of the engineers of the northstar. It has been modified from its original form. The procedure used to require running the engine up to the red line in second gear which we felt developed too much speed and was hard on the engine as it aged. The red line if I recall was 5800 and 6400 for the etc sts engine give or take. 70 works fine as a margin of safety.

I do believe you need a coolant flush to remove all the old coolant.I just had some fresh coolant put in a other vehicle.After just draining it and when refilled it roughly took about 3/4s (if that) of what it should of to refill it.

[BodybyFisher]

A little caddyinfo history,

I don't know if you are aware of it, but this site was graced by a genius that was part of the team that designed the Northstar. His name was Al Cline you may see someone referring to the guru, that was him. His knowledge ran deep with the Northstar. His legacy is here. HE is the end all be all when it comes to the Northstar. I am not 100% sure but its my understanding that he had health problems. I miss his insight. There are people here who carry his legacy, reasoning and understanding of the Northstar.

So needless to say I trusted him. THE Northstar is unique and required proper knowledge to maintain it properly.

The guru used to say drain and refill, period. Flushing with water you also can not get all the water out which creates a problwm balancing the coolant to 50/50 and you indroduce minerals into the cooling system. As far as using a shop to use a machine to backwash, the guru NEVER recommended that.

DRAIN AND REFILL, do not flush and never have it power flushed, now you know where that comes from.

As far as you continually asking what cadillac dealers recommend, i would trust the guru first and refer to the owners manual. I could care less what the dealer thinks in reality they should quote the owners manual that's all. You will not no mention of flushes, power steering fluid flushes or changes or.transmission flushes in owners manual. The reasons are discussed but mainly they are revenue generators.

[robjr100]

A little caddyinfo history,

I don't know if you are aware of it, but this site was graced by a genius that was part of the team that designed the Northstar. His name was Al Cline you may see someone referring to the guru, that was him. His knowledge ran deep with the Northstar. His legacy is here. HE is the end all be all when it comes to the Northstar. I am not 100% sure but its my understanding that he had health problems. I miss his insight. There are people here who carry his legacy, reasoning and understanding of the Northstar.

So needless to say I trusted him. THE Northstar is unique and required proper knowledge to maintain it properly.

The guru used to say drain and refill, period. Flushing with water you also can not get all the water out which creates a problwm balancing the coolant to 50/50 and you indroduce minerals into the cooling system. As far as using a shop to use a machine to backwash, the guru NEVER recommended that.

DRAIN AND REFILL, do not flush and never have it power flushed, now you know where that comes from.

As far as you continually asking what cadillac dealers recommend, i would trust the guru first and refer to the owners manual. I could care less what the dealer thinks in reality they should quote the owners manual that's all. You will not no mention of flushes, power steering fluid flushes or changes or.transmission flushes in owners manual. The reasons are discussed but mainly they are revenue generators.

Thanks for taking the time to fill me on the background of the forum and the advice of the guru Al Cline.Much appreciated.

[BodybyFisher]

My pleasure.

[winterset]

I believe The guru workes at Chrysler now. The N* was discontinued ~3 years now. Probably N* R&D was stopped 4 or 5 years ago.

[BodybyFisher]

Do you know that for a fact? How did you hear that? I heard he wasn't doing well physically.