IPD sale XeMODeX - Experts in Volvo Electronics Free shipping all USA - Experts in Brakes
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!

New member needs oil leak help

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

mtrdrms
Posts: 21
Joined: Thu Feb 04, 2016 5:32 pm
Year and Model: 1998 V70
Location: Connecticut
Has thanked: 0
Been thanked: 0
United States of America
mtrdrms

Re: New member needs oil leak help

Post by mtrdrms » Fri Feb 12, 2016 6:38 pm

erikv11 wrote:p0172 is almost always a leaky vacuum hose. Is the elbow on the passenger side of the intake manifold, put back in place? That is the most common offender.
Yes. New hose and new clamp fully seated. One of the intake manifold bolts stripped out of the head and it was too cold outside to helicoil. Could it be a gasket leak there?
I thought a vacuum leak would cause a lean condition? It does seem to be a vac leak however as my idle seems high (1000-1100).
Thanks all for the assistance.
Andy

User avatar
erikv11
Posts: 9485
Joined: Sat Jul 25, 2009 2:03 pm
Year and Model: 850, S/V70, 06 S60R
Location: Iowa
Has thanked: 81 times
Been thanked: 245 times
United States of America
erikv11

Re: New member needs oil leak help

Post by erikv11 » Sat Feb 13, 2016 9:51 am

Yeah the p0172 is a misunderstood code. According to VIDA, it actually indicates a lean condition. From VIDA:
The control module receives information from the HO2S about the fuel/air mixture in the idling and partial load ranges. If the fuel/air mixture deviates from λ=1 the short term fuel trim will compensate this by adjusting the injection timing so that λ=1 is achieved. When the short term fuel trim carries out this adjustment, its mid-point must be adapted by the long term trim. When the long term fuel trim has adapted the short term trim to a maximum value, DTC 2-3-2 (idling range - 0.48 ms to +0.40 ms) or DTC 2-3-1 (partial load range 0.773 to 1.227) and status message Upper Limit (lean fuel/air mixture) or Lower Limit (rich fuel/air mixture) will be set.
So ... P0172 actually indicates a lean condition by advising that the ECU has reached it's upper limit of compensation: It has added as much fuel as it's willing to add to rich up the mixture, but it still seems lean according to O2 sensor feedback.

I took all of this from a very knowledgable poster, it is over at VS in this thread http://volvospeed.com/vs_forum/topic/16 ... fuel-trim/

See also http://www.matthewsvolvosite.com/forums ... 5&start=20 for more speculation. That's why I say "vacuum hose leak" rather than simply "vacuum leak" because the elbow is not always under vacuum. Anyway the p0172 is indeed, almost always a leaky hose.

That's a good call on the IM bolt, that would probably do it. Also, I agree with abscate's opinion on waiting.
'95 854 T5-R, Motronic 4.4, 185k
'96 855 NA, 145k
'98 S70 NA, 220k (living out west)
'98 V70, T5 tune-injectors-turbo, LPT engine, 285k
'06 S60 R, 165k
'99 Camry V6 :shock: 125k
gone: '96 NA 850 210k, '98 NA V70 182k

mtrdrms
Posts: 21
Joined: Thu Feb 04, 2016 5:32 pm
Year and Model: 1998 V70
Location: Connecticut
Has thanked: 0
Been thanked: 0
United States of America
mtrdrms

Re: New member needs oil leak help

Post by mtrdrms » Sat Feb 13, 2016 1:22 pm

Thanks a ton! Seems to run great and holding steady at 20 mpg. Once the warmer weather comes, I'll tackle it.

mtrdrms
Posts: 21
Joined: Thu Feb 04, 2016 5:32 pm
Year and Model: 1998 V70
Location: Connecticut
Has thanked: 0
Been thanked: 0
United States of America
mtrdrms

Re: New member needs oil leak help

Post by mtrdrms » Wed Feb 17, 2016 6:14 pm

Ok so I think I fixed the p0172 and wanted follow up with all that helped me. I systematically replaced each vacuum hose and reset the cel. Then I would drive for a while to see if the light would stay off. It finally stayed off with the replacement of the brake booster line. It had a crack near the manifold and the old pinch clamp wasn't strong enough to keep it sealed. New hose and screw clamp and problem solved.
Thanks again.

User avatar
erikv11
Posts: 9485
Joined: Sat Jul 25, 2009 2:03 pm
Year and Model: 850, S/V70, 06 S60R
Location: Iowa
Has thanked: 81 times
Been thanked: 245 times
United States of America
erikv11

Re: New member needs oil leak help

Post by erikv11 » Wed Feb 17, 2016 7:54 pm

Good troubleshooting. Thanks a bunch for following up, really helps out the user base here.
'95 854 T5-R, Motronic 4.4, 185k
'96 855 NA, 145k
'98 S70 NA, 220k (living out west)
'98 V70, T5 tune-injectors-turbo, LPT engine, 285k
'06 S60 R, 165k
'99 Camry V6 :shock: 125k
gone: '96 NA 850 210k, '98 NA V70 182k

Post Reply
  • Similar Topics
    Replies
    Views
    Last post