Northstar Engines and System Technical Discussion Discussion, Losing Compression in Cadillac Engine Technical Discussion; I have a 2004 deville that has under 70,000 miles on the Northstar engine. This car is truly a car ...
I have a 2004 deville that has under 70,000 miles on the Northstar engine. This car is truly a car for Church on Sunday. The problem is the car began to stall. I took it to the shop and was advised it is losing compression. The car was tuned and I was advised that if the compression continues to drop, then I needed to replace the engine. What replace the engine that has less than 70,000 miles what a bummer. My thoughts (being a woman) is clearing the fuel line would help maybe clear some of the gunk that might have accumulated due to lack of driving. I put some fuel and carb cleaner to help remove gunk but it continues to stall, any suggestions, I truly need help. I feel like repairs guys are trying to take advantage of me due to my gender. Please help.
Not so fast, I just fixed one a few months ago that had lost compression due to "Aunt Sally goes to church" style driving causing the rings to accumulate combustion residues and stick in place, thereby losing their ability to seal in compression. These engines need occasional heavy throttle operation to stay clean, sort of like a self cleaning oven, it won't stay clean if you never heat it all the way up.
You guys have a sticky at the top of this forum labeled "Northstar Ring Cleaning Procedure" that features the Technical Service Bulletin (T.S.B.) that GM put out to identify this problem and how to best attempt to repair it. I used it to find success in repairing my customers 2000 DeVille DTS that was saved from the low compression grave and still running good.
Ms. Pewash I suggest you read these two posts and also print out the GM T.S.B. then take it to your Auto Technician and ask them to evaluate the prospect of performing the procedure on your car. The stalling needs to be further described as Ranger asked to help pin down the cause. It is likely as stated that it isn't related to low compression because the engine would be idling very rough for a while before it got to the point of stalling. If it has been tell us about that also. But if your "repair guys" are actually really competent and did a compression check as part of a normal tune up, as I do, and are telling you the truth then you may have a problem that can be fixed before it's too late by performing the prescribed procedure as I did. I'll look up the two posts and put a link to them here.
Automobile(s): Cadillac 78 Seville, 78 Coupe de Ville, 92 Sedan de Ville
Re: Losing Compression
I like your posts Vernon. I was with Ranger 100% when I originally read the OP. It seems we all know about the slow driving ring sticking issue, but it just comes up so rarely that it still slips by everybody. The thought of a 70k mile engine losing compression sounds like BS, but we have to remember this is the Northstar. Doh. Good catch Vernon.