850 with re-occuring missfire codes, valve guides?

[volvorod85]

So my sis's 95 850 turbo has had a re-occuring missfire code on cyl#3. She said it was running odd, low on power then cold, so i did a much needed tune up (plugs wires cap rotor fuel air) used all OEM stuff and bogi wires, code came back. I cleared it and it comes back after a few weeks it seems...cant relate it to anything, her driving habits havent changed....its kept maintained (via me). I cant feel a miss nor can i get it to miss....but i have a fear, ive heard rumor of valve guide issues in high mileage white blocks. This one has 180k on it, she has put 80k in 7 years on it since we got it at 99k. It doesnt really use any oil, no smoke from the pipe, breather system was replaced a while ago too. Its either an injector or valve guides....thoughts? I doubt injector as it seems to always run fine when im driving it anyway...but ive seen worn valve guides on other engines cause odd missfires, and missfire codes on more than one occasion

Mark

[ErikS]

80 bucks gets all the injectors cleaned and balanced, if its not them then move to the valve guide idea. Done a compression test on that cylinder?

[Chrisco]

10v or 20v?

[vlvman]

Move #3 injector to another cylinder, see if misfire follows the injector. Do a compression check and a leak down check. Sell car.

[wennstroma]

I've had a few where an injector would leak while closed. Pull the rail out of the intake and watch for drips or switch that injector to a different cylinder as mentioned.

When a cylinder gets washed down on one of these it takes quite a while to regain compression, so if it leaks overnight that could be why its running bad for a while when cold and likely when the code is being set.

[volvorod85]

I thought bout moving injector 3, maybe ill do that before condemning the head....Its not leaking down overnight....as after the tune up, her cold running issue went away. It was never a dead miss on start, it would only miss under heavy loads, she is often getting on the freeway 5 minutes after start up. Sellng it isnt an option, so its gotta be fixed. Am i right in saying tho that valve guides are problematic here in high mileage motors? and its a 20v turbo never got any 10 valves in the states

[volvorod85]

really, nobody??

[vlvman]

I have never heard of valve guide problems on 850's. I have heard of burnt valves on newer white blocks.

A miss on an 850 is usually plugs or cap and wires. You said you used volvo rotor, cap, plugs, and bougiecord wires, which should not be a problem. Did you check the plug gap?

850's are also bad about collapsed lifters if not driven regularly. Is there any lifter noise?

As far as I know they start off the cam sensor, then run off the crank sensor. Pull the crank sensor and clean it's tip might help.

[TrickMick]

Originally Posted by vlvman

I have never heard of valve guide problems on 850's. I have heard of burnt valves on newer white blocks.
A miss on an 850 is usually plugs or cap and wires. You said you used volvo rotor, cap, plugs, and bougiecord wires, which should not be a problem. Did you check the plug gap?
850's are also bad about collapsed lifters if not driven regularly. Is there any lifter noise?
As far as I know they start off the cam sensor, then run off the crank sensor. Pull the crank sensor and clean it's tip might help.

I've had a couple of these particular engines w/lifter / follower problems...it starts as an
intermittent on one cylinder and propagates .... *HOWEVER* once it begins it PROGRESSES
and *usually* in rapid order (it's a LUBRICATION CIRCULATION problem....

swop out the injector to another cylinder as Robert (aka vlvman) hath suggested...I'd also
do a plug and wire swop after that (assuming the injector is not fault)....look for a vac leak
as well...they CAN BE HARD TO FIND....

[volvorod85]

Originally Posted by TrickMick

I've had a couple of these particular engines w/lifter / follower problems...it starts as an
intermittent on one cylinder and propagates .... *HOWEVER* once it begins it PROGRESSES
and *usually* in rapid order (it's a LUBRICATION CIRCULATION problem....

swop out the injector to another cylinder as Robert (aka vlvman) hath suggested...I'd also
do a plug and wire swop after that (assuming the injector is not fault)....look for a vac leak
as well...they CAN BE HARD TO FIND....

The fuel trims are normal, so its not a vacuum leak, its not an ignition issue, as the misfire code on cyl#3 has not changed even after the tune up (note missfire code!), and yes, i gap every spark plug i put in, always...the times i dont, i have issues, so i just skip that and check the gap before installation, lol. Also a burned valve would cause the fuel trims to be outa wack, and it idles way too well to be a valve issue

But the lifter noise, yes! I have checked the oil to make sure its full, and today after she drove over, a few hours later i herd it start and its got lifer noise for a few seconds....ive noticed it over the last year or so its gotten progressively worse on a start after a few hours. It gets driven every day, regularly...doesnt really sit. Ivekept the oil changed every 4-5 months with conventional oil, 20/50, never had an issue.

So are we lookin at worn lifters then? theoretically if i put 20 new lifters in we should be good? cause it sounds like they are bleeding down faster than they should. But your saying a lubrication circulation issue, are we talkin sludge issues in the head? I mean, the tick on start goes away after a second or two, when oil preessure builds...but the lifters should hold the oil after shut down for at least a day or two before bleeding down enough to cause noise on a start. if the lifters dont bleed off the shouldn't tick on that start while oil pressure builds. That makes more sense than anything.

Mark

[wennstroma]

When they all tick all the time its usually a bad o-ring at the pickup tube in the oil pan.

Sometimes you get one where only one or two are ticking intermittently, we would add .5-1 quart of dexron atf to the engine oil and then drive it hard around the block once or twice then change the oil and filter. That would always un-stick them. Might clean the oil passages on yours . 20/50 oil sounds too heavy to me for these engines, but I can't say whether it would cause a problem. edit:(I'm no expert on hydraulic lifters, but could the heavy oil be pumping up the lifters/holding a valve open?).

I've worked on cars where all the lifters were ticking all the time for months and not setting any codes. Did you try swapping injectors yet?

[CEHepp]

Check the o-ring at the vacuum tree, it will leak a scary amount of air. I don't see that setting DTCs for misfires though.

[TrickMick]

http://www.2shared.com/file/12210882...Volvo_850.html

this is a ZIPPED FILE of the *complete 850 service manual*
hint hint.....

before you do anything else...get a MECHANICAL OIL PRESSURE GAUGE
installed and actually READ THE PRESSURES (cold / hot / idle / 4k rpm / etc...)

I'd also recommend a LEAK DOWN TEST just to be thorough on your "basic info"...

there are a couple of places where they can lose oil pressure (friggin *O-rings*)
LOTS of places for crap to accumulate in engines that aren't OIL CHANGED on
a decent schedule....

to do the job you're gonna have to make a DIY "cam cover/carrier" compresso to get to
the "work area" w/o ripping a bunch of fixing bolts out they sockets (having had to
rescue a head on one of those w/a gazillion TimeSerts for a shop whose techs weren[t
aware of the consequences....aarrggg....
see" http://www.tooladdiction.com/volvo%20tools%205452.jpg
cf: http://www.tooladdiction.com/

[volvorod85]

I just read bout the orings....i dont think its an oil presure isue as they do get quiet right away....but i will put a mech gauge on there to be sure....20/50 is one of the aproved weights in teh owners manual...and with 5 cars to service in my family at once, having 10/30 and 20/50 on hand makes my life easier for the mix of cars...hydro lifters shouldnt bleed down for a few days, ever try to compress one by hand? takes forever it seems....

i assume if i have oil pressure issues its a simple remove the sump and oil pickup and replace orings? or does it get more complicated...guesss ill look up removing the oil pump and go from there to see what im in for if i need to.

[JohnLane]

OP you mentioned............ "Ive kept the oil changed every 4-5 months with conventional oil, 20/50, never had an issue."

Now you've an issue. Modern synthetics do wonders. They keep things clean inside the engine such that issues as you describe don't take root and allow a 5000 mile oil change interval without hurting things.

[volvorod85]

Yeah, but 190k miles with no issue? i dont think the oil is an issue...and with the mileage im not switching to synthetic. And syn or not, i dont believe in 5k mile oil changes. Anyway....gonna check the oil pressure with a mech gauge and go from there, if its in spec its gettin lifters, if not itll get orings

[JohnLane]

My point is that it took this long for it to become an issue..... Now that the damage is done..... It will have to be fixed. Synthetic oils will clean it up.... But are not going to undo a need for a repair.

[volvorod85]

And i understand the completly, and my 850t had the synthetic treatment by the previous owner, so ive kept with it...i dont like changing it up on higer mileage cars though i know it would definatly benifit this one. And in the end, you cant say for certain that the motor would have been any better off with syn at this point than otherwise...if it is an o-ring problem, neither oil would have made a difference in the end...if its a lifter issue, then yes the argument can be made...but so can the mileage argument...either way, i do appreciate the advice, you gave me the answers ive been looking for, and we will see what the outcome is . thanks dude!

And when i do know what fixed it, i will reply to this thread

Mark

[volvorod85]

survey says oil pressure is good....cold start yeilded 80psi at idle...with max pressure at 100psi, which is where the relief is supposed to be. After warm up i have about 28-30 at idle, spec is 14psi min. And at 4000 rpm min 45-50 i think it was, i have 80....listening to it warm up too after a cold start, you can hear one lifter come and go....so a set has been ordered, along with a replacement coolant tank, hose, and abs speed sensor wiring kit for the left front wheel.

Mark

[TrickMick]

Originally Posted by volvorod85

survey says oil pressure is good....cold start yeilded 80psi at idle...with max pressure at 100psi, which is where the relief is supposed to be. After warm up i have about 28-30 at idle, spec is 14psi min. And at 4000 rpm min 45-50 i think it was, i have 80....listening to it warm up too after a cold start, you can hear one lifter come and go....so a set has been ordered, along with a replacement coolant tank, hose, and abs speed sensor wiring kit for the left front wheel.
Mark

*BEFORE* you rip the head off do a LEAKDOWN TEST....along w/a solid
COMPRESSION TEST...

your oil pressure numbers are fine (*thank goodness*!!)....do some careful
mic-ing of the bores the lifters ride in (KEEP THEM IN ORDER AS YOU
REMOVE THEM!!...measure the USED FOLLOWERS and do comparo's
w/the NEW ONES...adjust running clearances via different followers for different
bores....
when you go to re0install...*PLEASE* avail yourself of a cheapy "foam roller" to
lay down the "pink goo" - trust me on this - you'll LIKE the even coat you can
lay on the mating surfaces...it's the PRO WAY....

get the DECK CHECKED for FLAT AND TRUE..get the head HYDROTESTED
and checked for FLAT AND TRUE...be obsessive about the details..(*THAT* is what
separates the shade tree from the line tech....)...it's YOUR ENGINE..build it like
you mean it!

[wennstroma]

I've never replaced any lifters. As I said, I've worked on cars with all the lifters clicking constantly for months because of oil supply problems (pickup o-rings bad) and they never set a misfire code because of it.

Did you eliminate the injectors by swapping them yet?

[volvorod85]

Ok, well im not pulling the head, no reason to. Why at this point, on an engine that runs fine, doesnt have any drivability issues and has no indication of compression or valve leakage issues, should i do a leak down and compression test. Im not trying to be an ass but i dont understand why i have to go that far. Ive been doin this for a minute or two, and at the shop, if this was a customers car, with no obvious drivability issues, but an intermittent reoccuring code for a missfire, i wouldnt do a compression or leak down test. If I had an issue in either of those departments, I would have a constant problem i could reproduce, wouldnt you think? Low compression could cause a rough idle, odd cranking, low power...with excess valve leakage, youd get low vacuum, or uneven vacuum, low power, possible backfiring, lumpy idle, of which i have none. This would be easily found out with a lengthy test drive.

Again im not trying to be an ass, but i dont see why i would go to all that extra work, its not a race car, its a daily driver. And measuring the lifter bores, to match with the lifters? people actually do that in the real world for a normal street car? I understand your logic with a noisy lifter and possibly the oil seeping around it with a worn bore. But realistically have you seen issues with excessively worn lifter bores causing intermittent lifter issues, on a white block head, on more than just one occasion, with normal maintenance? Now you could argue a worn bore would cause a noisy lifter, but i would think it would be a constant tick, which this does not have, never has.....its got an issue with lifters bleeding down too quickly, which is an internal lifter issue. at 80psi cold at idle, i have a tick come and go, sometimes....fade in, fade out...if i had a bore issue, and that was causing a lifter noise, warm oil at 28psi at idle should much more problematic, and should make it more noisy more often when warm. When it sits for a few hours, you hear multiple lifters tick for about 1 sec after start, a direct sign of lifters bleeding down prematurely. They can sit on the bench and not bleed down, and it should be able to sit for 3-4 days between starts with minimal or no lifter noise, this does not, only takes an hour or 2 of sitting, so the lifters are defective.

Now i understand being very thorough when it comes to these kinds of problems, but sometimes going to the ends of the earth with tests and procedures isnt always necessary if you stop and think about how an engine works, how different failed parts or worn parts will effect the drivability of the car, power, or whatever the issue you are trying to repair. Realistically, half of those tests are not going to tell me anything other than the general condition of the engine, which I can tell you from experience, isnt going to help remedy this issue. part of being a diagnostic tech is knowing when to do those tests, and this is not one of those cases where it needs to be done. As you said you have had lifter issues with these engines, and when one fails the rest do shortly, and its a circulation issue...not a problem here. And consistently for the last few months the check lamp comes on after a week of driving, and the tick hasnt changed.

Anyway, believe me when i say thanks for all the info...something ive learned is if i dunno know off the top of my head and its not obvious right away, i ask the internet, see who else had had the problem, pick other peoples brains...then take that info and make the best choice for the issue. I have learned bout the o-rings in the oil pan, which i didnt know about. Please dont take any offense to this post, just expressing my thought process. Anywho, ill post back after doin the lifters, if the check lamp doesnt came back on

mark

[TrickMick]

compression and leakdown are BASELINE tests...if you've never done them
how do you know what is going on INSIDE THE CYLINDERS???
do them and log the results - it you have already done this - then you have a means
to COMPARE THE MECHANICAL "AIR PUMP" condition of the powerplant...

other suggestions were predicated on your removal of the cylinder head...if you
elect NOT to remove the head then so be it (save the post for when you DO
remove the head...)

and, YES, there are some of us out here who DO "measure up and define
clearances / weights / lift / duration / VE and other thangs".... YMMV

I'll take the recorded results of a dyno pull ANY DAY over "seat of the
pants EXPERIENCED observations"...just prudent diagnostics when
faced w/an INTERMITTENT problem....correctly calibrated ass-cheek
dynos are few and far between....

PLEASE *DO* investigate the "O-ring" issues further....

[volvorod85]

Originally Posted by TrickMick

compression and leakdown are BASELINE tests...if you've never done them
how do you know what is going on INSIDE THE CYLINDERS???
do them and log the results - it you have already done this - then you have a means
to COMPARE THE MECHANICAL "AIR PUMP" condition of the powerplant...

When you work in a shop, doing diagnostic work and repair, you tend to learn how excessive leakage past valves, and low compression can sound like, or feel like. If you do this for a living, day in day out, on every manufacture out there, you would know that there would be no reason to check that with this particular case. If this car was in your stall at your shop, I can be 95% sure youd never check leak down for this issue...maaaaaybe compression, but not likely.

Originally Posted by TrickMick

and, YES, there are some of us out here who DO "measure up and define
clearances / weights / lift / duration / VE and other thangs".... YMMV

I'll take the recorded results of a dyno pull ANY DAY over "seat of the
pants EXPERIENCED observations"...just prudent diagnostics when
faced w/an INTERMITTENT problem....correctly calibrated ass-cheek
dynos are few and far between....

This is not a numbers game for me, im not looking for the most HP and torque numbers, im not building a race motor, or trying to squeeze every ounce out of it. In the real world, this is not a race car. Its my sisters daily driver. Turn off your race motor brain dude, lol. Just cause its got a turbo doesnt mean you gotta get all crazy. Never and i mean never in any shop, where daily driver repairs are being made, would you measure lifter bores, unless wear with the bores has been problematic with those particular engines, or youve verified good oil pressure and replaced the lifters and still have noise....then and only then would most any technician would measure lifter bores. And this is not seat of my pants diagnostics, this is 10+ years of seeing and repairing electrical/mechanical issues on countless makes and models. Feeling how an engine runs, ive test driven cars and said its got a cam off one tooth on a v engine, had cars that run funny and via test drive and simple vacuum gauge readings went it needs a valve adjustment, and had that fix the car. Over and over again you think about the actual issue before geting crazy, you can better, quicker, and more efficently diagnose issues.

Originally Posted by TrickMick

PLEASE *DO* investigate the "O-ring" issues further....

Why? Ive already verified good oil pressure, why do i need to investigate anything further. The motor has no starvation issues. I can keep investigating it, reading more about how bad or shrunken o rings cause oil starvation issues...but didnt i just answer any possible questions? I mean, shrunken or hardened orings, can cause oil pressure loss...plain and simple. I dont have nay signs of oil press loss, so why would i goto the effort right now to remove the sump? With that logic I should pull the tranny and do the rear main too, while im at it reseal the oil pump, pull the head and do the head gasket...where does it end dude? Your probably referring to preventative maintenance, which I cannot argue with...and the orings will sit in my mind till i feel like pulling the pan off.

If i was rebuilding the motor, or the head, i would do a compression test/leakdown to see where everything was at before teardown, i cant argue with that, measure check remeasure...no holding back when major repairs are in order. Like I said, im trying to understand your logic for a daily driver, never will see a dyno, never gonna see a race track, might never even see 100mph. Have you worked in a shop doing heavy diagnosis on jap, euro and US cars? 3, 4, 5, 6, and 8 cyl motors? pushrod, OHC, flathead engines? fuel injected, carburated, multiple carbs, d-jet k-jet l-jet lh-jet, mototronic, bendix, GM SFI MFI DFI TBI CCC, ford EEC,

all im saying is there is no reason with this case to go that far, and what do you do for a living outa curiosity? heh i haven't had a good debate on a forum for a while, lol i usually dont care that much, so thanks for the discussion :-)

[TrickMick]

Originally Posted by volvorod85

- SNIP -
all im saying is there is no reason with this case to go that far, and what do you do for a living outa curiosity? heh i haven't had a good debate on a forum for a while, lol i usually dont care that much, so thanks for the discussion :-)

no worries mate...I'm a piss poor excuse for a mechanic...only been at this for 50+ years
I learn something new EVERY DAY....today I learned that I don't know
SQUAT about automotive mechanics *AND* I fear I am a reprehensible reprobate
that "steals customer time" doing useless investigations....I should be SCOURGED
I tell you - FLAGELLATED within an inch of my life....

everything I proffered had a REASON...you choose not to see it that way..and it's
FINE with me...."ALL ADVICE WORTH THE DO$H CHARGED"

850 engine design criteria:
http://www.pukema.com/vitmotor.pdf

go back after reading this and follow the "uprates" that Volvo introduced into the
"Modular engine line"....
SOLID LIFTERS
LARGER CAN BASE CIRCLE
BETTER OILING
und so weiter und so fort....
had a LOT of early T5's that died due to oil starvation brought on by "O-Ring"
failure down low....followers collapsed and some even seized in their bores
"ask the customers" about their JOY upon hearing the INTERFERENCE
MONSTER hath a visitation accomplished ..

BTW..LOTS of "ticking noise" from the front of the engine just MAY be belt
tensioner / sprocket issues....(these engine are / were KNOWN for that...)
but I digress.....

best of luck in your ministrations to "M'Lady's DD"....

the Mean Old Fat Bastard has left the building....