IPD sale Volvo Parts
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

Compression test results.

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.
1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70
Gtin
Posts: 73
Joined: Wed Aug 23, 2017 11:07 am
Year and Model: 98 v70
Location: Missouri
Has thanked: 0
Been thanked: 1 time
United States of America
Gtin

Compression test results.

Post by Gtin » Wed Feb 20, 2019 7:05 pm

Hey guys. So I recently bought a 98 v70 xc on the word of it needed a radiator. Got the radiator in and found out it has a few other problems. Namely it overheats, smokes white when warmed up and has a lot of blowby. So i was doing a compression test today and the results are as follows. Im counting cylinders left to right i dont know if that's how they really go.

Cyl 1: 180
Cyl 2: 165
Cyl 3: 140
Cyl4: 180
Cyl 5: 185

Obviously 2 and 3 have issues. But I'm not understanding what the deal is. I put a little oil in cyl 3 and it jumped up. So bad rings. But then I did another dry test on cyl 2 and it had jumped up as well. Ran the car to clear the oil and cyl 2 read good after that still for one test, then dropped back down to like 150. So cyl 3 definately bad rings. Cyl 2 is psychotic, check. But the coolant system is also pressurizing really quick. Like I can take the cap off the overflow to clear it and after testing just one cylinder with like 7 turns it's pressurized again. Is that normal? What are the odds of a bad head gasket AND bad rings? Im a little lost here honestly.



User avatar
WhatAmIDoing
Posts: 609
Joined: Sat Jul 30, 2016 1:13 pm
Year and Model: 1998 S70 T5M
Location: North America
Has thanked: 47 times
Been thanked: 48 times
Canada
WhatAmIDoing

Re: Compression test results.

Post by WhatAmIDoing » Wed Feb 20, 2019 7:15 pm

Bad head gasket 100%. Hope you didn't pay too much. I'd swap the engine with a 'good' used one, based on what you described. Cheaper than rebuilding this mess.


'98 S70 T5M - 270,000+mi
Knows enough to be dangerous :wink:

Gtin
Posts: 73
Joined: Wed Aug 23, 2017 11:07 am
Year and Model: 98 v70
Location: Missouri
Has thanked: 0
Been thanked: 1 time
United States of America
Gtin

Re: Compression test results.

Post by Gtin » Wed Feb 20, 2019 7:19 pm

Payed 650 for it. Plus 150 for a radiator... I was going to try some blue devil to limp it along for a while until I had some of the other projects my girlfriend is on me about out of the way. But the blowby and the compression jumping up on a wet test is stopping me. Those aren't normal signs of head gasket problems are they? And blue Devil won't fix rings.

Guy said he never drove it hot when I asked him 😂 I think he meant he would road trip it with no coolant and disconnect the fan just to be sure.

Any chance he also damaged the turbo? How would I check that before dropping $$ on an engine? Poor girl only reads something like 150k on the dash. Thought I had found a deal



User avatar
RickHaleParker
Posts: 2411
Joined: Mon May 25, 2015 2:30 pm
Year and Model: See Signature below.
Location: Kansas
Has thanked: 3 times
Been thanked: 258 times
United States of America
RickHaleParker

Re: Compression test results.

Post by RickHaleParker » Wed Feb 20, 2019 7:25 pm

It may just be carbon sticking the rings on #3. Seafoam eats carbon.

Pour some Seafoam down the cylinders and let it soak for a long time. Stuff some rags in the spark plug wells. Turn the engine over to push out the Seafoam. Install plugs and coil pack. Start engine let it run until the black smoke stops. Retest the compression.

Keep an eye on #3 make sure the it does not go dry during the Seafoam soak.
Last edited by RickHaleParker on Wed Feb 20, 2019 7:35 pm, edited 1 time in total.


Platform: P80 1998 C70, B5234T3, AW50-42, Bosch Motronic 4.4, Special Edition package, Plant: Uddevalla Sweden.

Platform: X40 (Nedcar) 2003 S40, B4204T3, AW55-50/51SN, Siemens EMS 2000. Plant: Born Netherlands.
----------------------------------------------------------------
1997 S90, B6304S, AW30-42, Bosch Motronic 4.4 - Sold

ZionXIX
Posts: 339
Joined: Mon Aug 11, 2014 2:47 pm
Year and Model: 1996 850 Turbo S/W
Location: Texas
Has thanked: 3 times
Been thanked: 22 times
United States of America
ZionXIX

Re: Compression test results.

Post by ZionXIX » Wed Feb 20, 2019 7:30 pm

RickHaleParker wrote:
Wed Feb 20, 2019 7:25 pm
It may just be carbon sticking the rings on #3. Seafoam eats carbon.

Pour some Seafoam down the cylinders and let it soak for a long time. Stuff some rags in the spark plug wells. Turn the engine over to push out the Seafoam. Install plugs and coil pack. Start engine let it run until the black smoke stops. Retest the compression.

Keep you eyes on #3 make sure the it does not go dry during the Seafoam soak.
Is an oil change recommended afterwards?



User avatar
RickHaleParker
Posts: 2411
Joined: Mon May 25, 2015 2:30 pm
Year and Model: See Signature below.
Location: Kansas
Has thanked: 3 times
Been thanked: 258 times
United States of America
RickHaleParker

Re: Compression test results.

Post by RickHaleParker » Wed Feb 20, 2019 7:37 pm

Seafoam in Oil does no harm. Seafoam is added to Oil intently for crankcase cleaning.
Just keep an eye on the Oil. If it becomes dirty do a Oil change.


Platform: P80 1998 C70, B5234T3, AW50-42, Bosch Motronic 4.4, Special Edition package, Plant: Uddevalla Sweden.

Platform: X40 (Nedcar) 2003 S40, B4204T3, AW55-50/51SN, Siemens EMS 2000. Plant: Born Netherlands.
----------------------------------------------------------------
1997 S90, B6304S, AW30-42, Bosch Motronic 4.4 - Sold

Gtin
Posts: 73
Joined: Wed Aug 23, 2017 11:07 am
Year and Model: 98 v70
Location: Missouri
Has thanked: 0
Been thanked: 1 time
United States of America
Gtin

Re: Compression test results.

Post by Gtin » Wed Feb 20, 2019 7:50 pm

I'll definately give that a go. I remember a long time ago a buddy of mine suggested marvels mystery oil for the same thing, is seafoam better or does it not matter much?



User avatar
RickHaleParker
Posts: 2411
Joined: Mon May 25, 2015 2:30 pm
Year and Model: See Signature below.
Location: Kansas
Has thanked: 3 times
Been thanked: 258 times
United States of America
RickHaleParker

Re: Compression test results.

Post by RickHaleParker » Wed Feb 20, 2019 8:13 pm

For carbon removal, Seafoam is better. Seafoam was designed as a cleaning product. Marvel mystery oil was invented as a upper cylinder lubrication. However one cannot say Marvel mystery oil won't unstick a carboned up up ring. Both are good products.


Platform: P80 1998 C70, B5234T3, AW50-42, Bosch Motronic 4.4, Special Edition package, Plant: Uddevalla Sweden.

Platform: X40 (Nedcar) 2003 S40, B4204T3, AW55-50/51SN, Siemens EMS 2000. Plant: Born Netherlands.
----------------------------------------------------------------
1997 S90, B6304S, AW30-42, Bosch Motronic 4.4 - Sold

Gtin
Posts: 73
Joined: Wed Aug 23, 2017 11:07 am
Year and Model: 98 v70
Location: Missouri
Has thanked: 0
Been thanked: 1 time
United States of America
Gtin

Re: Compression test results.

Post by Gtin » Tue Feb 26, 2019 12:52 am

Did the seafoam and got the compression up a bit to around 165 in cyl 2. Not perfect but I'll take it. Also ran some blue devil in it and I have noticed less smoke but the coolant system is still pressurizing, maybe not as much but it's hard to tell, I'm writing the blue devil off as a failure. Tried to test drive it today and had multiple misfires holding it down, didn't get time to check the spark or fuel, but the compression shouldn't be causing the misfire correct? 165 should be more than enough to allow combustion.



User avatar
erikv11
Posts: 8845
Joined: Sat Jul 25, 2009 2:03 pm
Year and Model: 850, S/V70, 06 S60R
Location: Iowa
Has thanked: 46 times
Been thanked: 145 times
United States of America
erikv11

Re: Compression test results.

Post by erikv11 » Tue Feb 26, 2019 10:00 am

First thing should have been to test for combustion gases in the coolant. Still worth doing.


'95 854 T5-R, Motronic 4.4, 185k
'96 855 NA, 140k
'98 S70 NA, 205k (living out west)
'98 V70, T5 tune-injectors-turbo, LPT engine, 275k
'06 S60 R, 155k
gone: '96 NA 850 210k, '98 NA V70 182k

Post Reply