Last post on Jun 10, 2013 at 7:03 AM
You are in the Chrysler LHS
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Chrysler LHS, Sedan
#1278 of 1409 Re: 1994 Chrysler LHS rough idle [tsurnick]
Sep 08, 2008 (6:06 pm)
I got the Idle air control valve today and installed it. I am also going to try the trick with the carb cleaner, spraying it near the intake manifold. The idle air control valve seemed to bring the idle back up where it needed to be. I will give it a good drive tomorrow to see if the hesitation is still there. It would kind of choke sometimes when the engine was running. Sometimes it would do it on the highway, some at idle. Most of the time at highway speeds. I will keep everyone posted on my progress as well. The other post sounds like more work, but it seemed to fix the problem. My car seems to run fine otherwise.
#1279 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [tuscanskipper]
Sep 09, 2008 (5:13 pm)
I did replace the idle air control valve and it helped a little. I got some carb cleaner today and sprayed it near the intake. I started spraying in back near the firewall but no fluctuations in the idle. then i came around to the front near the thermostat housing. When i sprayed there it started to change the idle. it bubbled a little as well. i could not tell if the leak was comming from the intake or the thermostat housing. how can i be sure? I replaced the theremostat and gasket about two months ago and there is no leaks. if the therm housing was leaking, wouldnt it leak antifreeze?. what do you suggest next?
#1280 of 1409 trunck ajar light wont go off.
Sep 09, 2008 (5:20 pm)
i recently put a light in the trunk. i got one of those lights from the auto parts store and unplugged the orriginal light that was already in the trunk. I found out which wire was hot and which was ground. the light works fine but now the trunk ajar light on the dash wont go off. I disconnected the light that i installed in the trunk to see if that would change or fix anything but it didnt. any ideas?
#1281 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [tsurnick]
Sep 09, 2008 (6:30 pm)
The thermostat gasket would leak water and not cause this problem. Your problem is failure of the manifold gasket, apparently it usually starts near cylinder No. 5.
When I removed my manifold gasket, I could see why these 3.5 Chrysler engines are known for this problem. The gasket is made of a material I have never seen a gasket made of before and never want to again.
Replace the manifold gasket and your vehicle will be transformed. Make sure you use a traditional high quality gasket, and NOT one of those Chrysler abortions.
If you don't have to take enforced breaks like I do, you should get this done in a day. The complete job took me seven hours.
Time to bite the bullet my friend. If you don't, you will end up with water in a cylinder, and or over heating problems. Mine had to be close on the basis of what I found on my vehicle.
#1282 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [tuscanskipper]
Sep 23, 2008 (2:47 pm)
Thanks for the info. I am preparing my self for the job this weekend. I have a slight valve cover leak as well so i plan to do those as well. Would you have any other tips or points to watch out for when i am doing the job sat? I noticed that one of the people posting on here was talking about the fuel Rails? I know what they are but should i remove them or do you have to? It may have been you talking about it. I noticed that the car goes up in idle every now and then, it jumps to about 1200 rpm and back down to about 800 average. when you are sitting still, it just does that. when you are driving if makes the vehicle jump (kind of feels like its popped into gear) but its just the idle speed doing that. I was assuming that this was caused by more air sucking into the manifold . I also need to replace the oil pan gasket, but i may save that for a later day. Its seems easy to get done except for the front area where the bolts are kind of under part of the frame. I wonder who thought of that.
#1283 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [tuscanskipper]
Sep 23, 2008 (2:57 pm)
thanks for help but have huge problem. two bolts are frozen and both feel that with any force they will snap. what can i do?
#1285 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [barouk]
Sep 23, 2008 (3:11 pm)
you may want to try some liquid wrench. saturate all around the bolt and let it stand for a while before trying it again. hopefully that will work.if they do break, you can get a set of bolt outs (they are kind of like drill bits that go backwards.) lowes may have them if the parts store doesnt. i have my parts store on speed dial for reasons such as that. usually those guys are pretty smart.
Thanks and i hope that helps
#1286 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [tsurnick]
Sep 27, 2008 (3:15 am)
I agree with the advice about the bolts.
You will need a plenum gasket, manifold gaskets and the two fuel rail gaskets. I would also recommend a thermostat housing gasket. Also if you can get one, a gasket for the heater hose outlet on the back of the manifold. I could not find one of those, so if you break it you will have to make one, likely.
I would recommend not decoupling the fuel rails, as you may do damage it will be hard to repair. You will have to remove the fuel rails. I would recommend removing the thermostat housing so you can set them to one side, without decoupling them.
Getting the old gasket off is hard. I polished all surface with the small Scotch Brite pads on my small air angle grinder.
It is fiddly to keep the manifold and fuel rail gaskets in place. You will need something sticky to hold them. I used a product called form a gasket. I also put a bead of blue RTV sealant round the waterways.
Sorry for the late reply, but I'm visiting England currently.
#1287 of 1409 Re: Mystery of the rough idle on the Chrysler 3.5 V5 solved! [tuscanskipper]
Sep 29, 2008 (2:38 pm)
I finally went and did it. I replaced the Intake gasket, the valve cover gaskets and the thermostat housing gasket. no leaks. I have another problem now. the idle is fine unless you put the car in gear, then the idle either drops to about 600rpm or the car dies all together. I cant seem to find any vacuum hoses that are loose or anything. any ideas? otherwise, the car seems to run fine. it hovers right around 1000 rpm normally till,like i said, you put it in gear.