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View Full Version : RPM surging, rough shifting, overheating



Heraclid
05/19/2010, 06:48 PM
Ok, couple of days ago the VX started having surging RPM's as I was driving it. It has done this a few times before but not this bad and it is very infrequent - pretty much thought no more of it. But like I said, this was worse.

The next day (yesterday), it drove fine for a little while, then it started again. Only this time it was shifting real rough and started running super hot. If you put it in park or neutral it revs up even more. Pulled into a parking lot and checked under the hood, water reservoir was low so I walked over to a store and got some water and filled that up. Ran fine from there to the house. Got a check engine light, disconnected battery and cleared it, no more light.

Today, ran fine for a little bit, then surging started again. No clunking from the tranny this time, but it got super hot again sitting in a drive-thru. Actually got a little better from there to the house. Had plenty of water. Got a check engine light again.

Anyone got any suggestions?

I'll try to get codes tomorrow since they just opened an Auto Zone real close and I think it can make it that far.

WormGod
05/20/2010, 06:59 AM
Yep, that CEL might be just the info you need right now. Hopefully narrow down the 5-10 different things that everyone is about to post. ;)

Heraclid
05/21/2010, 05:01 AM
Didn't get to deal with it yesterday, but should later today.

ICV is fine, in fact it's a pretty new one I recently put in. I periodically clean the usual places with carb cleaner. Air filter not great but not too bad. The water was low as previously stated, so I filled that up.

One thing you'd normally check right away but I hadn't checked because I check it pretty often? Oil. Figured that was fine. I check it often because I worry about it even more than usual with a VX for reasons we all know about. I've seen no indications of leaks. But sure enough, the dipstick came back practically dry. Will get underneath this morning and see what I can tell from that. So that's part of the problem at least. That makes me feel pretty stupid.

Seems intake manifold gaskets would be a good thing to look at too, will see. Never had to replace any, maybe I'm due.

Also found a little twist cap sort of like an over-sized one for a tire valve stem. Found it sitting between the rear edge of the hood and the driver's side wiper arm. Turns out it goes on the fuel rail on the driver's side, where there's a little valve stem that squirts fuel if you depress it. It's a miracle it ended up where it did and not lost forever down below.

Haven't been here in a long time, but it's been busy and the VX just won't cause me enough problems, LOL. Did have a melted electrical connection at the gas tank cause some stalling a while back. Also got a very slow power steering fluid leak and it's easier and cheaper to top it off every now and then than to replace the pump. Other than that stuff, just typical maintenance. Oh yeah (and this is a biggie for me), the window has never worked right despite all the "fixes" posted here. It dropped free into the door a while back because the adhesive holding the clips and glass together failed. Re-attached it but it didn't hold. Now if you use it at all the glass will come free of the lift arm and drop free into the door. But as far as getting me from A to B, it's done alright.

VX KAT
05/21/2010, 08:53 AM
:hj:

Oh yeah (and this is a biggie for me), the window has never worked right despite all the "fixes" posted here. It dropped free into the door a while back because the adhesive holding the clips and glass together failed. Re-attached it but it didn't hold. Now if you use it at all the glass will come free of the lift arm and drop free into the door. But as far as getting me from A to B, it's done alright.
For $65, strongly suggest you get the SBC metal brackets from Tim...can't believe the glass hasn't already broken.....and I bet it's much more than the cost of the brackets. Good luck, hope you can get it resolved.
http://www.streetboutiquecustoms.com/vx.html:ot:

atilla_the_fun
05/21/2010, 09:12 AM
I'll sell you mine for 50, the same metal brackets - I bought them from Tim but didn't have to use them because it was the rubber lining that was causing my problems

Heraclid
05/21/2010, 02:08 PM
Atilla, I think I'll take you up on that... PM me what you need me to do... thanks!

Haven't been on here for a while, but had seen something about those brackets. Mine wasn't working before the glass broke out of the tabs, but at least it might fix that, and since it's a nice wide bracket, maybe the window will start coming up straight again (it cants forward)? It did seem to get pinched in the rubber at the front, but I've tried the fixes for that and it still misbehaves. I just flat out can't use it right now. Haven't for so long I'm used to it, but it is aggravating at drive-thrus and such and I always liked riding around with the windows down some too.

atilla_the_fun
05/21/2010, 08:50 PM
so, I've tracked the progress of the window problem from mine and everyone else's experiences and it all starts with the rubber. The reason every VX window fails over time is because the rubber dries out and clamps down on the front edge of the window. This then wears out one (the top one) of a set of 3 small plastic sliders that normally keep the window straight (they attach to the regulator). Once these pieces start wearing out, the added pressure from tilting forward breaks the plastic window clips.

This was not a system that was designed to last. I enlarged the entire front track using a set of pliers. I also added silicone (or other waterproof) grease liberally into the track. The worst part was having to fix the plastic sliders that had worn out. These follow the center rail and allow the regulator to push the window up straight. I wrapped electrical tape (something slippery) around them until the window could no longer tilt back and forth. Since they are a funny shape, I needed something I could wrap around them that wouldn't wear out with repeated up and down contact with a metal surface.

Tom's brackets can only replace broken window brackets - they can't fix these other issues, and you'll either have to fix it yourself (the rubber & regulator sliders) or buy a new set of regulators (and rubber).

When I bought my VX it came with a set of weathertech wind deflectors. I can now say that THE WEATHERTECH WIND DEFLECTORS CONTRIBUTE TO OR CAUSE OUR WINDOW PROBLEMS. They fit snugly inside the railing and once your rubber starts to dry out, they add pressure at the front of the window. This causes the plastic pieces to wear out faster. Just don't use them - even now that I have the problems fixed I can't uses them or the issues return. Nothing should ever enter the window railings on the VX, there isn't enough space to fit the rubber, the window and the wind deflector without increasing friction to an unsupportable level.

http://www.vehicross.info/gallery/data/500/thumbs/VXwindow1.JPG (http://www.vehicross.info/gallery/showphoto.php/photo/17826)

89Vette
05/21/2010, 10:41 PM
Seems intake manifold gaskets would be a good thing to look at too, will see. Never had to replace any, maybe I'm due.


That was one of my first thoughts too. But, after looking at the intake gasket set picture, it doesn't look like water (antifreeze) circulates through the intake manifold of a VX. Because it's running extremely hot, I would suspect antifreeze involvement because it creates lots of extra friction (when it gets into the cylinders) plus it burns hotter. (See if you see any white smoke when it acts up.)

As such, I might be more inclined to suspect a head gasket problem. Certainly water has to flow up to the heads. When a head gasket blows water can get into the cylinders and oil can get into the radiator (fluid). Maybe that's where your oil went?

You need to stop driving it until it get figured out. With the 3.5L engine history, this could lead to BAD news -- if you push it! (I could already be bad news.)

Heraclid
05/23/2010, 11:55 AM
Thanks a bunch 89Vette - it is running fine right now, just for a couple of short trips. Plan is to get it to a good mechanic tomorrow for a thorough inspection. I thought I did see white smoke once, but I'm not even really sure and I didn't notice it the next time. But a lot of oil and water seems to have gone somewhere real quick, so that makes a lot of sense. I will mention your thoughts on this to the mechanic. Haven't even spent much time on it myself, things have been kinda crazy and now my brother's wife is in labor and I'm about to be an uncle.

Heraclid
05/28/2010, 10:10 PM
Diagnosis was a faulty throttle position sensor, had it replaced. We'll see if that's really all there was to it. Still idling a little bit high.