Login Register

Can Cylinder 5 Misfire / Clogged Injector Unclog?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

Post Reply
AnyMajorDude
Posts: 12
Joined: 23 September 2018
Year and Model: 2000 V70
Location: Southern NJ
Has thanked: 3 times

Can Cylinder 5 Misfire / Clogged Injector Unclog?

Post by AnyMajorDude »

2000 V70 with 150K miles has been diagnosed with a clogged injector and misfire in cyl 5.

Fuel injector cleaner has been added to the fuel since diagnosis. I do not have any codes or other metrics.

Can this resolve on its own by running the vehicle at idle or local driving? What are dangers of trying this?

Thanks in advance.

User avatar
abscate
MVS Moderator
Posts: 35332
Joined: 17 February 2013
Year and Model: 99: V70s S70s,05 V70
Location: Port Jefferson Long Island NY
Has thanked: 1511 times
Been thanked: 3829 times

Post by abscate »

It’s so rare that I don’t think we have enough data to help here.

How sure are you on the diagnosis

0= crystal ball told you
1= Mechanic said “ it’s a clogged injector”
....
10. You have removed all th einjectors and tested the flow rates into graduated cylinders
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
Link to Maintenance record thread

User avatar
oragex
Posts: 5347
Joined: 24 May 2013
Year and Model: S60 2003
Location: Canada
Has thanked: 102 times
Been thanked: 352 times
Contact:

Post by oragex »

as above, don't trust right away what mechanics say

may as well be a leaking valve seal, very common on these engines

greenellie
Posts: 2
Joined: 26 March 2019
Year and Model: 1998 V70 GLT
Location: Bellingham, WA

Post by greenellie »

How are your vacuum lines? Also might be a wonky valve seal. Misfires around that mileage are more often caused by vacuum leaks. I had to replace a few until I finally found the leak that was causing my misfiring. I hope your car is doing better, get back to me! 8)

AnyMajorDude
Posts: 12
Joined: 23 September 2018
Year and Model: 2000 V70
Location: Southern NJ
Has thanked: 3 times

Post by AnyMajorDude »

I don't trust the local mechanic, that is why I am seeking forum advice. I will inquire if the vacuum lines and valve seals were considered. Idling and local driving... yes or no?

User avatar
erikv11
Posts: 11807
Joined: 25 July 2009
Year and Model: 850, V70, S60R, XC70
Location: Iowa
Has thanked: 294 times
Been thanked: 767 times

Post by erikv11 »

AnyMajorDude wrote: 26 Mar 2019, 10:22 2000 V70 with 150K miles has been diagnosed with a clogged injector and misfire in cyl 5.

Fuel injector cleaner has been added to the fuel since diagnosis. I do not have any codes or other metrics.

Can this resolve on its own by running the vehicle at idle or local driving? What are dangers of trying this?

Thanks in advance.
I wouldn't run more than a couple weeks on a clogged injector (if indeed, that is actually the problem). A clogged injector will make the cylinder run lean = excessive heat = burnt valves = thousand bucks. A week should be ok, depending on the demands on the car.

A good way to know if it is the injector is to swap them between two cylinders, see if the misfire follows the injector.

#5 misfire is often a leak in the intake manifold gasket.
'95 854 T-5R, Motronic 4.4, 185k
'98 V70, T5 tune-injectors-turbo, LPT engine, 304k, daily driver
'06 S60 R, 197k
'07 XC70, black, 205k
'07 XC70, willow green, 212k
'99 Camry V6 :shock: 153k
gone: '96 NA 850 210k, '98 NA V70 182k, '98 S70 NA 225k, '96 855 NA 169k

Post Reply
  • Similar Topics
    Replies
    Views
    Last post