I'd like to renew PCV system on my '98 V90 (oil separator, the hoses...), got a kit from FCP for that. The kit includes an intake manifold gasket, so I'm planning on undoing the intake manifold bolts, loosening the bottom one next to engine mount and moving the manifold to get access. Done this kind of job once on a B230F, wasn't too hard to get the whole intake manifold removed, and I was able to get a bunch of things cleaned -- the manifold, the throttle body, the EGR valve and the injectors. Tried to find a writeup for the job on a B6304 car but couldn't find anything too detailed. Maybe better access can be gained by removing the alternator, I think someone had mentioned that. Any tips for doing the job are appreciated.

I'm also suspecting a leak from one (or more) of the injectors into the cylinder -- the car has an issue with occasional misfires on startup and there's sometimes smell of fuel around the car that I believe could be unburned fuel getting into exhaust. Was thinking of getting the injectors checked and maybe replacing with another set to test (if I can find some decent ones at a local junkyard). Got a set of new seals for the injectors too.

"low mileage" 1998 V90 157K -- currently my project car

Take the alt and power steering off to change the black box.

The two relays on the shock tower cause all sorts of problems, pull them apart and look for a dry solder joint or buy two new ones or swap them around as they are both the same part number. The are called radio suppression relays of all things.

I'm working slowly on this project (not much spare time), so far got the injectors off, and some things caught my attention. The current injectors have only two seals on them, one at the fuel rail, one on the intake manifold side (see picture below). The parts that I got from FCP include "3 o-rings", "one yellow protective sleeve" and "one support ring" (see the second pic). I also got Volvo branded injector seals P/N 6842408 (pictured). Looks like at least the Volvo seals were missing (or should they be there?) -- I'm trying to figure out what to do with the other parts in the injector service kit as well... The intake side of the engine looks a little dirty (pictured) so wonder if that's a sign of the previous leakage from around the injectors.
Now almost got to that oil separator box...



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'98 965

Are you going to have the injectors clean by a machine and tested???

I'll probably be doing this job on my wife's car very soon and hoping for some warm weather.

Have you verified good compression on all cylinders? Maybe a leakdown test? Hate to say it, but I had to do head gasket on our V90 at 242k.

Haven't gotten there yet, was looking to get that compression test kit from Harbor freight for a while, guess that would be my next step if the cleaning and new injector seals won't help. Was thinking to do that beforehand, but figured that hey, I'll fix the PCV system that's clearly not doing its job first and will go from there.
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'98 965

Well, maybe I should've started with a compression test... I took the intake manifold off, there's some nasty looking goo under cylinder 4 (as in "P0304 engine code"), and some under cylinder 3 as well... Am I looking at replacing the head gasket, or could this be stuff leaking from the injectors or the intake manifold gasket? (The gasket was pretty oily when I took it off, and some bolts that attach the manifold to the head felt loose when I was removing them).

A few comments on replacing the manifold: the bottom attachment was a 13mm nut, not a 12mm bolt as some reports say, took me while to realize that. I couldn't imagine loosening it reaching from the top (maybe possible but too much stuff like wires and vacuum lines around it, not to mention the throttle cable with its brittle attachment and the brake cylinder). The biggest obstacle to get to it from below is the wiring from the transmission that runs just under it. I removed two 10mm bolts attaching the harness and loosened a third one (too hard to remove as the engine mount is in the way). Also removed one 12mm bolt attaching the harness to the engine block and unhooked the connectors from the bracket on the transmission (did not open them up, just moved them). That created just enough space to get a standard 3/8" 13mm socket with a universal joint and a long extension (I used a 10" plus a 6") to the nut and break it loose. The bolt is on the intake manifold, and you only need to loosen the nut enough to move it out of its slot.

Before undoing any bolts on the manifold I would recommend removing the plastic vacuum tree just about the vaccuum booster hose (attached with a single 10mm bolt -- remove the bolt and pull the thing out); I tried to do it after and I felt that maybe it wasn't the best way around it. Old vacuum hoses get pretty brittle and crack easily, better to leave them in place. The brake booster hose can of course be disconnected at the booster, then you can wiggle it out to get out with the manifold.

After getting this step done I'd say that pulling the intake manifold on a 6-cylinder whiteblock is not that much more work than on my B230FD. (My 1994 940 has an EGR valve, at least the 6 cylinder is free of that hassle.)

RE: misfire. Could be injector seals, but might also be your coils. Have you pulled them to check for cracks?

Checked the coils, replaced with a different set (previously removed from my other car, they're old but the car was running fine with them). Same symptoms. Replaced the spark plugs with a new Volvo set -- old ones were somewhat fouled. The car started to run like a champ with a new set, but then went back to intermittent misfires on startup. I'm figuring something is getting into the cylinders, so injectors is my next thing on the list. Wouldn't be surprised if some of the seals were bad, I doubt that anyone has ever touched these injectors in these 157K...
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'98 965

You may want to use an OBD-II code scanner connected the OBD port connector jack and check for stored fault codes that may indicate spark plug-fouling causes.

The 700-900 FAQ makes rather brief and useless guidance on OBD-II.

A local auto parts store will offer free use of a generic OBD-II code scanner while in their car park.

Hope that helps.

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I've had code 304 (misfire on cylinder 4) come a couple of times, when the shaking got particularly noticeable. It hasn't come back since the coil change, but the engine still shakes on startup, gets back to normal after about 30 seconds. Doesn't do it every time, sometimes just starts as it should. No other ignition-related codes.
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'98 965

Something must be causing your plugs to foul, though.

A wet or dry plug fouling?

Does your RWD 90 series have Turbo? How many miles?

Something engine control has not set as a fault code yet your engine is running rich.

You have verified proper ground and power connection between the battery and alternator to the engine. Poor power connection can tend to a rich running condition.

Fuel rail pressure regulator? Though you would get rich or lean / rich running fault codes from Motronic.

You have tested sensors like both 02 sensors or the ECT sensors for function? Or the AMM / MAF? Though, again, Motronic would set codes, I guess. I have no idea the fault tolerance or 1998 S and V RWD 90 engine control fault tolerance.

On 1989+ 240 is can be rather forgiving, yet not so far as plug fouling. Tho the single ignition power stage (you have two in S & V RWD 90 series) is not monitored for OBD fault, yet connector corrosion can halt the engine. Maybe before hand one would have weak spark to the coil (or coils in your instance).

Just a guess fest. Celebratory in spirit, certainly!

Hope that halps.
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Spark plugs were wet when last removed. I'm guessing could be fuel or oil fouling... haven't got so much experience to be able to tell... Also concerned about the gas smell after the engine starts (I think more pronounced while the engine is cold), so I'd like to think my problem is fuel-related. Another thought is that I put synthetic oil (Mobil 1 10W30 High Mileage) at the last oil change, and as far as I can tell it had some cheap stuff in it before (from PO) which hasn't been changed for a while. This could be a far shot, but maybe the slicker synthetic oil in the engine that got used to dino, started finding its way into combustion chambers and creating this sort of trouble. If that would the case I sure hope it's reversible (the car ran for about 1K miles with Mobil 1).
The car still runs pretty nice all these problems notwithstanding, so I'm hopeful things are going to sort out with not too much work.
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'98 965

I doubt it is oil getting into the cylinders. There is a school of thought that a gradual transition to synthetic is recommended in an engine has always been using conventional. For example, try mixing 50/50 synthetic and conventional in your next oil change.

If you pull the intake manifold, there is no reason to remove the alternator. Replace the injector seals and pintel caps while you're at it. The bottom nut on the manifold is a god-awful one to reach. Have fun.

You want to check this for a how to!
https://volvoforums.com/forum/volvo-s90-v90-40/s90-breather-box-intake-manifold-87184/

The misfire can also be a bad ignition coil, but it is a perfect time to get the injectors clean.

if you need some, let me know I have some spares and also spare coils if you like
to play with one.

speedy

Thank you for the link, it's just what I was looking for!
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'98 965