32 replies to this topic

[MadeInJapan]

So I took the intake manifold off of the 850 (non-turbo '94) last weekend and cleaned up the PCV system (that's another long story- there wasn't any oil in it and all lines were clear- weird)....anyway, after I got it all back together, replacing all rubber lines with silicone and doing a good job (I thought) of lining everything up, the car idles horribly. Thought I had turned the air lock on the Evap line that runs to the vacuum tree the wrong way (black of the black/white cylinder faces the tree, right?) and so changed that so air flows to the vacuum tree but not the other way and tried to reset everything but still a CEL comes on...at idle it's horrible....even some engine bucking...once it starts going, there's no problem at all. At idle it's almost like the exhaust is partially clogged. Once on the highway the CEL will go off...back in stop and go traffic the CEL is back on... fuel trim code and sometimes a throttle speed sensor partially working code. I was really stumped until I looked at where the intake manifold bolts onto the engine again and I may have found the problem. I'm seeing that (just barely because most of it is covered up) that the left upper edge of the intake gasket is down further than the rest of the gasket... Could it be that it slid down while I was tightening everything and that the gasket itself is covering part of #1 intake? If this is so, then that cylinder is going to be starved for air- symptoms of bad idle. Probably when the car is at highway speeds, air will push past it and all is okay. Are there any insights here to this issue? I suppose I should have used just a tad of silicone or something to hold that damn gasket up while I was installing it. It is only held on by the lower screws until you get it buttoned up and I can see where that side could have slid down. I really don't want to have to take the intake manifold off again to pull that gasket up or better yet, just replace it with a new one. Anyway- the community's thoughts on this would be appreciated.

[Distort]

So I took the intake manifold off of the 850 (non-turbo '94) last weekend and cleaned up the PCV system (that's another long story- there wasn't any oil in it and all lines were clear- weird)....anyway, after I got it all back together, replacing all rubber lines with silicone and doing a good job (I thought) of lining everything up, the car idles horribly. Thought I had turned the air lock on the Evap line that runs to the vacuum tree the wrong way (black of the black/white cylinder faces the tree, right?) and so changed that so air flows to the vacuum tree but not the other way and tried to reset everything but still a CEL comes on...at idle it's horrible....even some engine bucking...once it starts going, there's no problem at all. At idle it's almost like the exhaust is partially clogged. Once on the highway the CEL will go off...back in stop and go traffic the CEL is back on... fuel trim code and sometimes a throttle speed sensor partially working code. I was really stumped until I looked at where the intake manifold bolts onto the engine again and I may have found the problem. I'm seeing that (just barely because most of it is covered up) that the left upper edge of the intake gasket is down further than the rest of the gasket... Could it be that it slid down while I was tightening everything and that the gasket itself is covering part of #1 intake? If this is so, then that cylinder is going to be starved for air- symptoms of bad idle. Probably when the car is at highway speeds, air will push past it and all is okay. Are there any insights here to this issue? I suppose I should have used just a tad of silicone or something to hold that damn gasket up while I was installing it. It is only held on by the lower screws until you get it buttoned up and I can see where that side could have slid down. I really don't want to have to take the intake manifold off again to pull that gasket up or better yet, just replace it with a new one. Anyway- the community's thoughts on this would be appreciated.

Same shit happened to me, after working on that thing for 6 1/2 hours. It ended up being the vacuum line that plugs into the left side of the intake manifold. Thing popped out on me, was a pain in the ass to get back in once the manifold was on.

[MrWinkey]

I really sounds vacuum related. Especially at the intake runners from your description. With it idling spray some carb cleaner around the intake runners at the head and gasket and see if the idle changes. Sure sounds like the gasket dropped down or something. You do know that when installing the gasket you put your bottom bolts in first through the gasket then slide the intake down on top.

[MadeInJapan]

Yes, I did all of that (lower bolts first, slide the manifold onto the bolts, etc.)...my manifold does not have any vacuum hose on the passenger side like some...mine has it underneath...ask me how I know- I saw it and told myself, don't let that one get disconnected- it will be a bear to get back on- long story short, after I got everything put back together, I noticed the hose dangling- it was another 2 hours before I figured out how to get under the manifold w/ my hand (not small hands) and with the help of my son under the car (with a flashlight) going, "left, right...no, up down...you just missed it dad, etc." I finally pushed it back on. I'll try the carb cleaner around the manifold....so what if it's a leak there? What do I do now? I guess it would have to come off again or is there some way to seal it from outside?

[AlvinL]

I think there may be a crease in the gasket that's letting unmetered air in.

[MrWinkey]

If it's leaking at the intake you need to take it back apart...

[MadeInJapan]

Thanks everyone- I'll check it as soon as my son gets back with it.

[Martynj]

Definitely sounds like the intake gasket. I had exactly the same symptoms when the intake gasket went south on my 940T.

An unlit propane torch will also raise the idle at any vacuum leaks. I've found it to be a better indicator than the carb cleaner but either one does work.

[Marzocchi]

Sad to say but if you used a intake manifold gasket from FCP, your problem is there. Get a Victor Reinz gasket (OEM) or genuine volvo.

[MadeInJapan]

Sad to say but if you used a intake manifold gasket from FCP, your problem is there. Get a Victor Reinz gasket (OEM) or genuine volvo.

Okay, thanks for your input regarding the intake manifold gasket. I'll pick one up at the dealer tomorrow or the next day- I did use a FCPG one

[jdlc]

Okay, thanks for your input regarding the intake manifold gasket. I'll pick one up at the dealer tomorrow or the next day- I did use a FCPG one

I used the fcp kind for our V70 NA and my previous 94 855T, and didn't have any issue.
I do have the green oem gasket now waiting for install on my T5M when I service the pcv.

[wheelsup]

I used the fcp kind for our V70 NA and my previous 94 855T, and didn't have any issue.
I do have the green oem gasket now waiting for install on my T5M when I service the pcv.

Are you not supposed to reuse them? I did, seems to run fine.

[MrWinkey]

Are you not supposed to reuse them? I did, seems to run fine.

Suppose you could but why ?

[MadeInJapan]

Thanks for everyone's input...I sprayed carb cleaner around the intake manifold while at idle and guess what? The engine surged like crazy so I've got a pretty bad leak. I'm getting an OEM gasket from the dealer tomorrow and pulling the intake off again this weekend.- FCPG intake gaskets are crap. I should have just left what was there in place and reused it. What a let-down.

[MrWinkey]

Actually you probably should have purchased OEM stuff from the start? For "gosh sakes" you own a Volvo, so I assume you wash your hind end in a bidet already? With that said, how much money did you really save on your job when you have to tear it back apart a second time? Good thing the labor is free!

[Dan2286]

Sad to say but if you used a intake manifold gasket from FCP, your problem is there. Get a Victor Reinz gasket (OEM) or genuine volvo.

Are they known for being bad "out of the box"? I used one when I did my PCV system and I have had no problems after about 100 miles. This was my first time doing the PCV system also.

[MadeInJapan]

To answer the above series of questions- you know, I really didn't even think about the gasket- I bought all OEM timing belt parts- tensioner, roller, pulley, water pump, belt, etc. at the same time so I spent plenty- Did the timing belt during my spring break in March and put off the PCV job until last weekend... It was a bear and I replaced all hoses with silicone....I also cleaned the EGR and replaced brake pads and flushed with new brake fluid and replaced power steering fluid, transmission fluid and coolant and fixed the odometer gear and added an iPod adapter- so yeah, I've been getting this car up to snuff with good stuff (I'm not cheaping out)- just didn't think that the gasket would be any different OEM or FCP- didn't even bother to ask- Live and learn I guess. If I had thought about it and had known, I would have definitly bought an OEM gasket, from the dealer if I had to- I'm not cheap w/ repairs....anyway, lesson learned. Thanks for everyone's help. Oh, and when I lived in Japan, we did have a bidet...if I could find one over here, I would have one still.

[betterthingstodo]

when I lived in Japan, we did have a bidet...if I could find one over here, I would have one still.

FCP manifold gasket worked okay for me – I ran into a problem with the little bracket on the bottom right manifold bolt which gave me a similar but much worse rough idle than the condition you describe. The bracket ended up between the manifold and the block, an easy oversight for a n00b like me. The manifold bolt threads through it and it needs to be held away from the block while reinstalling the manifold.

Also just wondering, did you torque the manifold bolts when you reinstalled them to 14 foot lbs?

[wheelsup]

Suppose you could but why ?

Because you'll end up like MIJ...

[boltz]

Actually you probably should have purchased OEM stuff from the start? For "gosh sakes" you own a Volvo, so I assume you wash your hind end in a bidet already? With that said, how much money did you really save on your job when you have to tear it back apart a second time? Good thing the labor is free!

Personally, I won't settle for less than a genuine Volvo bidet from Waltrip in an official blue box with the Volvo logo on it. I always order the one with the latte in it.



-JH