Most of the time if the VALVE SEALS (not valve guides) are bad you will get smoke on start up. Like get435 mentioned do a compression test. Then come back with you numbers. If the head gasket is blown into that cylinder then a compression test will tell you But if that was the cause you would know it.

 

if it was the stock head is prob the guides ther are mad out of a materal that dose love to crack than the seals go trust me on this one i had the exact problem with my gs and it was the guides and on a ford before that guides were bad as well.

 

If it is the rings would the car even be worth trying to save?It has about 140,000 miles on it.

 

depends on how much you like the car if you like it and dont mind puting about 1200-1400 into it for a car that is going to run strong for another 150,000-250,000 than ya its worth it.

 

alright,I got the compression test done today and the mechanic said it did well.He said they were all below 50.So I got the valvecover gasketand the plug seals.I'll get the car back tommorrow.How long should I run it before I take out a plug and see if the problem has been solved?

 

It shouldn't take long at all maybe a day or 2 should give you an idea if there is a problem.

 

Wait you had a compression test done and it was 50psi?!?!?!?!?!? Please tell me you mean 150psi!

 

all he said was that it was below 50,I assumed it was psi...lol.Hey does anyone know what a stock 99' 420a has got?

 

umm....it should be up above 130psi(most cars are). my suggestion...take it to another mechanic. that mechanic doesn't know **** if he thinks below 50psi is good. i would get the headgasket checked.

 

I don't understand.This guy is a head mechanic at a Midas shop.Shouldn't he know what he's doing?I can't even swear thats exactly what he said,I have a terrible memory and as soon as I heard the words,"Everything checked out fine" My mind said "YEA!!!I don't have to spend 1200 to 1500 dollars!!!"