Volvo AWD 850 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 9/2004 850 INDEX

[<<] [>>]

THREADED

THREADED EXPANDED

FLAT

PRINT ALL

MESSAGES IN THIS THREAD

REPLY TO THIS MESSAGE

SAVE

low engine compression, clogged PCV? 850 1994

posted by Shawn 2003 on Fri May 23 16:20 CST 2003
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS]

[IGNORE ALL POSTS] [RELATED]

Hello! My engine has been getting poor gas mileage (15 mpg city, 19-20 Hwy) for the last several months. It has developed a slight and occasional oil leak, am told that the PCV may be clogged as the crankcase pressure is very high, and the engine piston pressure has fallen to 50-65% of what it should be. I was told this engine is on its last legs! A replacement is expensive. It has 127K miles on it, mostly highway.
What are my options? Is it worth boring out the cylinders, get new pistons and rings, get another used engine (price?), or replace this with a non-Volvo engine (price? source?) or just run it til the end (when?) This is new territory and I appreciate your expertise please.
Thank you.

REPLY TO THIS MESSAGE

SAVE

low engine compression, clogged PCV? 850 1994

posted by someone claiming to be Frank on Sat May 24 02:23 CST 2003 [RELATED]

Do yourself a big favor and get another professional opinion from a tech who knows your car, like a Volvo master tech. That engine shouldn't be THAT bad at that mileage UNLESS it's been abused, neglected and/or driven overheated for a long time.
Normally, those engines should go well over 200K miles w/o major problems. If someone who said it has too much blowby said "might be a clogged flame trap" (non-turbos only) then why didn't they just fix it?
The "piston pressure" was determined by....? (compression test, specs?) or cylinder leak down test? (best way to determine actual area of compression loss if so).

REPLY TO THIS MESSAGE

SAVE

low engine compression, clogged PCV? 850 1994

posted by Shawn 2003 on Sat May 24 05:52 CST 2003
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS]

[IGNORE ALL POSTS] [RELATED]

Thank you for your response. the flame trap was removed when this issue first occured months ago. They did the cylinder leak down test and gave me the graphic results and specs to me. The mechanic has been working on my other cars (volvo, audi, vw) and is well known for their quality work. Having owned 3 other volvos I thought this car should go well over 200K also. I appreciate your input, and welcome any other thoughts you may have.
Have a safe weekend.

REPLY TO THIS MESSAGE

SAVE

low engine compression, clogged PCV? 850 1994

posted by someone claiming to be Frank on Sun May 25 03:46 CST 2003 [RELATED]

Your options are then:

Have it rebuilt (hone cylinder walls, new rings, etc) IF those doing the work are good, experienced and the labor isn't too high.

or replace the engine (used or reman from Volvo).

Replacing it with a used engine might be the cheapest way to go but one takes the risk that the replacement engine might not be perfect either and could have higher mileage that what you now have. All used car parts places will tell you that their replacement engines have "30,000 miles on it" (NOT too likely) so there's some risk going that route.

The OEM Volvo reman will be like new but they're not cheap either. If you plan to keep the car for a long time, like another 10 yrs, then I'd suggest a reman as it'll be worthwhile to you in the long run.

<< < > >>

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.