QuestionHello. MY LHS had a very rough idle, and gassy fumes coming out of the tailpipe. I could hear air leaking all around the intake manifold, so I changed those gaskets. The engine runs MUCH better, but 'shakes' a bit still, and stalls on deceleration (usually when pushing brakes to stop or corner). Could this be Spark Plug wires? The spark plugs, intake manifold (upper and lower) gaskets, TB gaskets, and EGR tube gaskets are all new and I can't hear them leak (anymore). I tried checking the plug wires' resistance, and got values all over the board, none seemed to match at all. Plug wires a little costly, and hate to waste money if not needed. Thank you very much. Mike.
AnswerIt appears to be an egr issue. You might want to remove the valve and try cleaning out its passageway and also lubricate the valve stem and make sure that it is free to move. Finally once you think it cleared out and the stem is moving, try blowing thru the valve to verify that it is truly closed.
Thanks for the generous rating.
Roland
Hi Mike,
I have a couple of suggestions.
First why not check the valve stem of the egr valve to make sure that it isn't stuck ajar. You will find a slot into which you can insert the tip of a screwdriver and then move it back and forth against spring tension in one direction. If it seem to hang up then I would spray some solvent or WD-40 on the stem where it enters the valve and try and loosen up the action. An ajar egr will cause a poor/no idle when slowing down or even at rest.
The other action would be to get the fault codes that might be stored in the engine controller. You can get a partial and less definitive readout using your ignition key in all likelihood. I would try to readout the engine controller memory for fault codes which would tell us whether it has noticed something wrong which would give us direction. Take the ignition key and turn it:"on-off-on-off-on and leave it on" doing that in an elapsed time of 5 seconds or less. I mean by 'on' just to the place where the key sits when the engine is running and you are going down the road.
Then watch the 'check engine' light which remains 'on' when the key is in the run position but the engine isn't running. Soon it will start to flash, pause, flash, pause, etc. Count the number of flashes before each pause and keep track of those. Then do the key trick again to repeat the process and thus verify that you have the numbers accurately. Then group the numbers in pairs in the order that they occured to form two digit numbers which are the fault codes. The last such number will be 55 which is the code for "end of readout". Then either write me back and tell me the other numbers for further advice and/or go to www.allpar.com/fix/codes.html where you can find a list of what the codes mean. When you write back tell me which engine you have and also tell me if the car originally was delivered in California or Canada so I know how its pollution equipment is set up. Then I'll be in a position to tell you what to do about the fault codes.
You also can get an OBD-II type code readout by plugging a reader into a receptacle under the dash. An Autozone or other parts store may do that for free or a shop will do it for around $40. Those fault codes are 4 digit numbers preceeded by a P. So get those is you can. You may want to erase all the prior codes first and then drive the car for a bit before doing the readout in case you may have fixed some of the old ones. Just disconnect the battery for a few minutes to do the erasing, but then you should expect to get one of the new codes as "battery supply to the engine controller disconnected recently" so don't get thrown by that one.
I will wait to learn about the codes before giving you other advice.
Roland
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