# Almost bogs out??



## quasarcav (Mar 25, 2004)

Hello,

My 85Z bogs really bad after it has heated up, all i have to do is barely press the gas and the revs drop to almost stall. I have checked the vacuum hoses and I think it is the FPR!

Any ideas?

The revs are good before it is heated but after it takes some pressing to get above 2000rpm, once you are above 2000rpm everything is fine. alot of blue/white smoke comes out but goes away after driving for a while.

Thanks in advance.


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## Spongerider (Nov 18, 2002)

quasarcav said:


> Hello,
> 
> My 85Z bogs really bad after it has heated up, all i have to do is barely press the gas and the revs drop to almost stall. I have checked the vacuum hoses and I think it is the FPR!
> 
> ...


Blue/white smoke is not good, oil burning. Get compression test this could be the problem.


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## quasarcav (Mar 25, 2004)

I dont really want to dump alot of money into this thing. If it is the piston rings then i will probably part out and cut my losses.

I read on here that if the fuel regulator is screwed up that fuel may enter through the PCV and spit fuel/oil out the tailpipe.

I think the white smoke is just condensation because it is still cold out here and i just started in in the morning -5C.

We did a top engine clean and changed the oil and the smoke wasn't nearly as bad. the engine only has 192000kms what am i looking at for a new one?


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## Spongerider (Nov 18, 2002)

quasarcav said:


> I dont really want to dump alot of money into this thing. If it is the piston rings then i will probably part out and cut my losses.
> 
> I read on here that if the fuel regulator is screwed up that fuel may enter through the PCV and spit fuel/oil out the tailpipe.
> 
> ...


Since you have that many miles on her you might also want to change the PCV.


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## quasarcav (Mar 25, 2004)

UPDATE:

I changed the PCV and gave it a good oil and filter job. she runs alot better but smokes like hell sometimes. So I pulled all the plugs. they all checked out except for number 6. it was oil soaked and the plug wire was all stressed and easily broken.

I am going to replace all the plugs/wires tonight to see if it makes anything better but i fear the worst with cylinder #6.

any ideas? any quick fixes or easier ways then pulling the head off and possibly changing piston rings.

Am i right to think only worn rings or valve guides would soak a plug like this?


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## Zen31ZR (Mar 24, 2004)

And stem seals. Excessive valve guide wear is kind of unusual , the whole rest of the engine would be in just as bad a shape. You may have a piece of crud jammed in an oil control ring , which will cause that smoking , or the stem seals on that particular cylinder are almost shot , and likely on the whole head on that side. Stem seals are fairly easy , it's possible to do stem seals with the head still on the car. I'd worry about loose valve guides if the valve stem can rattle around in there like a bad ball bearing , but otherwise little or no side to side play means the guide is still good. Most engines this age need stem seals anyway , and you might as well do a new T-belt while you are at it. A little security goes a long way.


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## quasarcav (Mar 25, 2004)

would a piece of crud cause the oil burning to be intermittant? I took it for a drive on saturday and no smoke for an hour. started it up sunday afternoon and it smoked alot!

The plugs look the same on all other cylinders. I am going to change the plugs tonight and give an update tomorrow.


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## Zen31ZR (Mar 24, 2004)

quasarcav said:


> would a piece of crud cause the oil burning to be intermittant? I took it for a drive on saturday and no smoke for an hour. started it up sunday afternoon and it smoked alot!


M-kay in that case , probably not a piece of crud. It smoked bad rigth after the start-up? how about 10 minutes later. Bad oil smoke on startup is caused by oil dribbling down a valve stem through a bad stem seal and collecting in the combustion chamber itself. Same thing if you've been sitting idling for a while , you'll get very bad oil smoke , like say coming off a stoplight. In that particular case , oil is being sucked into the combustion chamber through the bad stem seal , by idle vacuum. The oil generally won't burn off til the engine is under load.


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## quasarcav (Mar 25, 2004)

Okay, so if it is just idiling it wont fully burn it off, but when it is fully heated there will be less oil?

Start-up= most oil smoke
5min later= slight blue in exhaust at idle, when revved smaller cloud comes out
10min (operating temp) even less blue, will still come out if revved.

While driving= blue at stoplight but none or little while cruising.


I have heard some horror stories about stop-smoke additives, is this a good thing to do or will i be risking more damage?

What kind of cash and time will it take to fix the stem-seal?

Thanks


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## Zen31ZR (Mar 24, 2004)

quasarcav said:


> Okay, so if it is just idiling it wont fully burn it off, but when it is fully heated there will be less oil?
> 
> Start-up= most oil smoke
> 5min later= slight blue in exhaust at idle, when revved smaller cloud comes out
> ...


Yeah what you describe is absolutely typical stem seal failure symptoms. 
I wouldn't bother with the no smoke additives , at best they don't work as claimed and at worst they can do odd things to the inside of your engine. I wouldn't risk it. 
Stem seals are not expensive , the last time I bought a set for a 16 valve engine it was about $45. You'll also need to buy a valve spring compressor , have typical hand tools to remove the cam(s) , and a piece of rope to stuff inside the combustion chamber through the spark plug hole. This prevents the valve from falling into the chamber when the spring is taken off of it , though it likely wouldn't fall all the way into the cylinder. If you are gonna pull both heads for this (recommended) then get a new timing-belt and whatever else is required , tensioners and such , and new head gaskets. This should run you close to $100 or so , for all the pieces involved. $150 tops.
The advantage to pulling the heads is you can also clean off the valves while the heads is disassembled , at this late date they are likely VERY dirty and killing some of the airflow. If you are gonna have a shop do it , I honestly can't tell you a price , but ballpark is $500-$700 or more , for disassembly , cleaning , new stem seals and gaskets , and reassembly.


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## quasarcav (Mar 25, 2004)

UPDATE: Yeah.....

So i didn't want to open the engine until i absolutly had to. I asked my gearhead neighbour if their was anything i could do for a temp fix. He said to change my plugs/wires, change the oil and put duralube in it. I'm pretty skeptical about oil additives but i thought 15 bucks wasn't bad for a try.

Changed everything and fired it up and she blew smoke for about 30 seconds. then it stopped. Revved it up and no smoke, took it for a ride and no smoke.

Then i really tried to bag on it and no smoke came out. Let her sit for a couple hours and started it again, little bit of smoke on startup then none.

I dont know how long this fix will last but at least i have some time to save money until i need to open her up!

Thanks for all your help [email protected], I wouldn't even know where to start.

:cheers:


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## Zen31ZR (Mar 24, 2004)

quasarcav said:


> UPDATE: Yeah.....
> 
> So i didn't want to open the engine until i absolutly had to. I asked my gearhead neighbour if their was anything i could do for a temp fix. He said to change my plugs/wires, change the oil and put duralube in it. I'm pretty skeptical about oil additives but i thought 15 bucks wasn't bad for a try.
> 
> ...


I generally don't trust all the "majic" oil additives , but if it worked for you , that's good. I think all it probably did was make the oil a touch thicker so it has more trouble being sucked into the combustion chamber. I use 15W40 myself , but I'm also about 100 Hp over factory.


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