1996 850 Turbo, Rough idle, new PCV didn't fix it...

Post by **erikv11** » 01 Oct 2013, 00:43

I agree with everything in BKM's last post except changing the oil and the comment about lubrication - don't waste your time and money on oil while you are troubleshooting, the weight of the oil is not going to have anything to do with it chugging and running rough while at idle.

It seems likely there are a couple problems here, one to do with the idle (also try this simple very cheap task: clean the idle air control valve) and one to do with the oil on the plug. If the residue on the #1 plug is fuel then you may have a burned valve there (check compression to test) or hopefully something less dire like a bad plug wire, if it is oil then you may have a badly leaking valve stem seal. Which will shortly become a burned valve if left as is ...

futureboycolin · Post by **futureboycolin** » 01 Oct 2013, 01:01

The buildup on the plug is definitely oil, and it's not seeping in from the plug boot. Is the valve stem seal something that I could feasibly replace on my own? I've done the PCV, timing belt, water pump, serpentine belt, wheel bearings, brakes, etc... at one time I was considering doing a head gasket job on another car. I don't have any specialized valve or engine block precision tools, but I might be able to borrow some.

Edit: quick note about valve stem seals...I don't have ANY smoke from the exhaust, just an occasional soft popping noise in 1st gear. I reaaalllly don't want to do a compression test...ugh, if the results are bad I'm going to be so bummed.

Suppose I should clean the EGR and the throttle body while I'm at it?

Post by **erikv11** » 01 Oct 2013, 07:47

Definitely clean the throttle body. Remove and clean the IAC at the same time. I have never owned a Volvo with EGR so will refrain from recommendations there.

Changing the valve stem seals is a very long but do able in-car job. You would need a couple special tools. I have never done it myself, only pulled the head and dropped it off at the machine shop. But as you suggest, if the valve stem seals are going out then there should be a puff of blue smoke at startup or when you rev it after idling a long time. Thing is, I don't know what else would cause oil on just one plug.

Knowing the compression test result gives you very useful info ...

futureboycolin · Post by **futureboycolin** » 01 Oct 2013, 12:18

I won't have much time to do anymore work on the beast this week, so here's hoping it keeps running strong.

As far as the engine not being lubricated enough, the disptick reads that the oil is topped up. Planning on replacing all plugs, but with NGK coppers...never had good luck with Bosch plugs. Right now I'm running Autolite cheap-s#!t plugs. I replaced the rotor, distributor, an wires with OEM in January, but had major oil-spewing problems after that, so I will check to make sure none of that is fouled. Also will check the cam position sensor for fouling. Will clean up the EGR, the Throttle body, the IAC and check all vacuum connections again.

I read the codes, here's what I've got:
P1310 - misfire, which I've had before
P0301 - misfire in cylinder #1, same deal, already knew that
P0102 - NEW, MAF code, so I'll clean it, and check to see if it's a refurb or an aftermarket, but I'm fairly sure it's OEM
P0245 - NEW, Turbo wastegate solenoid? Should I pull the turbo and clean everything up back there?

Also have 3 monitors ready - Misfire, Fuel and Comp

Post by **erikv11** » 01 Oct 2013, 12:24

p0102 is more often a vacuum leak, than the MAF itself. Did you check that PITA vacuum elbow on the end of the intake manifold, kind of below the power steering pump?

p0245 check the wiring to the TCV, is it plugged in and making good contact. TCV is on the side of the air cleaner.

Post by **MoVolvos** » 01 Oct 2013, 12:55

futureboycolin wrote:No, I was hoping that the new PCV would resolve any blow-by issues that were fouling the cat, o2 sensors, causing misfires or fouling spark plugs. I will check the plugs tomorrow and see if they're clean, and read the codes to see if there's any new info.

Also planning on cleaning the o2 sensors to see if that may be the cause of the engine running rich?

**

Hi erikv11,

The oil change to 5W-40 is a needed part of the troubleshooting process. It is also needed to potentially solve the original blow-by issue causing the CAT, plug(s) and O2 to foul. It is way down on this list for the current issues because "futureboycolin" needs to by process of elimination make sure all the other parts are in good working order and which item made a difference then finally change the oil so it does not potentially foul any more parts (plug(s), O2) during the troubleshooting process.

Another member "mattman" in the Post below was having an oil consumption, blow-by issue which was eliminate with a change back to DINO per FCPEuro's article linked below.

"Mattman": "Hey all, turns out it was the oil. Too low a viscosity for the old girl...", "Oil changed to Castrol GTX 10W-40 with a quart of 15W-40, smoke is very minimal now, i.e. drivable.", "Currently smoke-free, with no fluid losses after 350 miles of driving."

Mattman, as in my personal experiences in the last dozen or so year saw a drastic change besides being the solution to our problems. Not all cars will respond that dramatically to an oil change because the motors are in better shape but all high mileage motors will benefit greatly going to a 5W-40. This weight is ideal for all weather except the extreme winters where you may want to go with a lower VIS oil. If you must have Synthetic use Shells T6. Found this to be much better than Mobil.

https://www.matthewsvolvosite.com/forums ... =1&t=59045

http://www.fcpeuro.com/page/what-is-the ... for-my-car

Blessings,

BKM

**

Post by **erikv11** » 01 Oct 2013, 13:26

RIght - mattman's car ran fine, it just puffed some smoke. Here, OP's is not idling properly etc. And you raise good points about possible blowby that I was not thinking about, so maybe "way down the list" on the oil change. But not off the list.

futureboycolin · Post by **futureboycolin** » 02 Oct 2013, 22:13

The vacuum elbow at the end of the intake manifold is good, I clamped it on myself. I just fixed up a new secure PTC nipple, as that vacuum elbow was just too big to stay on the nipple. I know that's not the culprit. I also installed a new, tighter fitting vacuum hose that goes from the barb near the bottom of the MAF to the tree on the airbox, so that isn't it either. I cleaned the MAF (which is a Bosch, OEM), for good measure, and the P0102 code has since gone away. I'm fairly sure it was the vacuum hose under the MAF and not the sensor itself.

I'm still throwing the P0245 turbo wastegate solenoid code, the P1310 and P0301.

I smelled the exhaust today when I started up the car, and it did indeed smell like unburnt fuel. I also replaced the plug on cylinder #1, and the old one smelled a bit like fuel as soon as I pulled it.

Tomorrow I'm seafoaming the engine, cleaning the throttle body, the IAC and the EGR if present. I will report back afterwards. I'm a bit worried because as soon as I changed the plug, the idle smoothed a bit, and the hesitation/stalliness when slowing to idle was gone, but has since returned with a bit of vibration after driving a bit tonight.

I plan to try 5w-40 Standard oil after I change out the seafoamed oil on Friday, and will put in a new set of NGK copper plugs at the same time. Compression test results will have to wait til after the weekend probably. The car has had an intermittent hard starting issue for a little while, and I'm going to pull the cap and rotor and check the cam position sensor for oil fouling. I did spill a bit of coolant on the alternator and serpentine belt when I was doing the PCV, could that affect the idle? Also the damned dipstick handle broke off today, so I'm gonna have to JB weld that back while I wait for my new dipstick tube.

On the bright side, my avg MPG went from 8.9 to 9.2 today! Hooray!!

Post by **MoVolvos** » 02 Oct 2013, 23:55

**

Keep at it! As for the Dipstick use a brake cleaner not carb to degrease really well wiping as you go followed by 91% denatured alcohol and wiping well also. Don't touch it with your fingers afterwards. Let it sit for a day in a dry spot. The following day warm it up (not heat) with a hair dryer and apply an epoxy. Mine has lasted around 1.5 years now.

By the way that number 1 cylinder may have an Injector problem. I am not familiar with the workings of it however your car is running rich and fouling up the new plug already it seems?

I've heard and seen some Youtube videos of Sea Foam damaging cars so I would stay away from it even though some people swear by it. I've had excellent results with the 503 for problematic cars and of course the Chevron stuff is always good as a preventive. The 503 really cleans and quiets down the car like as if you were running a Premium Premium Fuel if that was possible or such a thing.

http://www.pelicanparts.com/catalog/sho ... co_pg9.htm

Blessings,

BKM

**

futureboycolin · Post by **futureboycolin** » 03 Oct 2013, 15:16

I'm going the Seafoam route, since I already bought it, but I'll just make sure to vacuum it up in the brake booster, rather than on the throttle body vacuum tree.

What the heck can I do about the P0245 code besides get a new TCV...

I'm starting to think that I should've just poured Seafoam into the oil trap via the snorkel, and let it sit, added it to the oil system, and just left the old PCV on there.