95 F355 - Low Compression/Poor Leakdown

$11-12k for valve guides with the major? Yikes.

Ken

 

Dude, something sounds rotten in Denmark. 80-90 psi on a compression test on all your cylinders? Is that a compression test, or a leak down test? I almost wonder if the car would even run with compression that low, and if so it would run very poorly, and not for very long. That low of compression would either be valves or rings just about totally shot. If it was rings, no way in hell you wouldnt be blowing oil. If it were valves, they would all be burned, and losing more rapidly. No way they would all be that equal on all 8 cylinders. The only way it could be that low all around would be mis-timed belts.
Valve guides worn out? How in the world could anyone diagnose that without tearing the motor down? Sorry guy, but there is nothing I see pointing to those being bad, and there is no way to check guide clearance withough pulling the heads. I suppose if you pulled the cams, and removed the bucket followers, you could try wiggling the stems around but somehow I doubt this was done on your car, as you cant remove the belts very easily with the motor in the car. Bad valve guides usually burn oil at long periods of idling, or on hard downshifts where the high vacuum pulls the oil down from above. But at a quart in 3000 miles, you really arent using any oil.
I think you need a good second opinion, and perhaps try tackling the 30K service on your own. I doubt there is anything wrong with your motor. Let me know how this goes. I'll be very curious to learn more.

 

I still stand firm by what I said. Somehow I feel the $11K estimate could easily double.

 

Continental Autosports of Hinsdale (Chicago area) has told me that a valve guide replacement on a F355 would run about $18,000. I believe this includes a full 30K service as well.

 

Well, I can see there's no 355 in my immediate future. How much of that is parts and how much labor?

Ken

 

My valve guide replacement and 30K service was $11K from FoA. $18K is WAY out of line.

 

I think it's high time to stop, sit back, and re-evaluate everything REALLY carefully.

As Paul (krowbar) says, they cannot make that diagnosis without pulling the heads. It is also well known that valve guide "problems" tend to show up early in a car's life - not at 49K. Before they go ripping things further apart, I would have them check the current cam timing. That being out is the best explanation for a uniform 80-90 in all cylinders. Of course, their compression gauge could be stuffed....

Something just isn't right here.....

Dave

 

Was the compression test done with the engine out of the car (using the remote starter)? If so it would have to have been done cold, which may not correlate well to most other testing results. It just seems improbable that ANY motor would have really poor and almost identical compression results on EVERY cylinder. I'd ask them for a retest before committing to any pull-down starting.

Secondly, if you are looking at that sort of cost I'd go for a second opinion. Find another shop of good reputation & get the engine taken over to them for a report. Heck you're talking lots of bucks here - what's another $500 or so getting a proper diagnosis BEFORE you're in too deep. Just like if you are looking at expensive medical treatment - best to get as many opinions as possible & then make up your own mind.

 

A good pal of mine is searching for a 355. He has looked at several, all portrayed as in perfect condition. They have all had poor leak down numbers (20 - 25% on multiple cylinders) when tested (audible through the intake and exhaust). Some of these cars had been well driven (20 - 25K miles). Another pal just dumped his 355. 35K miles. Guides. $18K estimate to fix. It is not unique to low mileage cars.

Good luck.
Philip