FYI for those people with overheating issues with their VX

[wintermute]

Sharing my recent experiences here, for the record. I was having intermittent overheating issues usually traveling uphill or when stopped in traffic so I went through the entire cooling system eventually replacing the water pump, thermostat, radiator and all hoses, and the fan clutch assembly. My problem persisted. Driving up a hill, the temperature gauge would climb from below the half-way point to just shy of the H line...

I ended up finally replacing the engine coolant temperature sensor and haven't had the problem since on the same routes.

This sensor is cheap, and easy to replace. Entire job took less than 5 minutes, and doesn't require a coolant drain. Something to consider if you find yourself trouble-shooting a heat problem.

[ZeroSix]

Where is the coolant sensor located? TIA

[wintermute]

Where is the coolant sensor located? TIA

Page 1211 of the shop manual. (Section 6E-442)



http://www.vehicross.info/gallery/sh...hp/photo/23326

[ipd]

Add me to this list. I was running with the windows down & the heater BLASTING on the way back to Phoenix from California last night. A/C works great most of the time, but it becomes impotent when the temp gauge is pegging. By the time I got back & parked it, I could hear BOILING coming from the overflow tank--it was about 2 hours after dark & the A/C hadn't been on for at least an hour. I had topped off the coolant overflow tank before I left.

It gets WAY worse in town & with stop/go than on the highway. I tried babying it back here as much as I could--I hope I didn't do any damage to it. I'm not even sure where/how to proceed. I plan to flush it & pressure-wash the radiator (remove any caked-on dirt that might be obstructing airflow). Beyond that though, I'm at a loss.

Did we ever get a resolution on this? I'd rather get this nailed down in Phoenix--where there's more shops/people deal with cars overheating more often--than wait to get to SLC & have to work with a smaller market & less options.

[VX KAT]

Did you do a search? There's a few detailed threads on this, and how most solved this problem.

[ipd]

I did. I'm trying to piece everything together. So is the general recommendation the RD radiator, the newer-spec OEM fan clutch, and the original-spec OEM blades? Is this the "magic combo"?

And my apologies. There's YEARS of overheating issues in threads all over. Plus NONE of the links to other parts of the forum (in threads) work for me...so I have to manually search everything and cross my fingers.

[VX KAT]

The Admin said some things aren't working yet on this updated version.

If you've tried replacing the thermostat, relacing or flushing the radiator, and still not resolved, most (including myself) found the fan clutch was the solution. I recall VXorado bought an aftermarket one that didn't work out or died soon, so then got an OEM and it solved his problem. I also recall some strongly recommend against flushing radiator as it will flush out things that may be plugging a small hole, and the radiator may start leaking.

You can test your fan clutch by spinning it and seeing if there's resistance, but I can't recall which way it's supposed to be.

We never did figure out what benefit the redesigned fan blade served.

Some have tried adding electric fans, but most have found that didn't work either, even though it seems it should. I recall there's one owner that has had great success with his electric fan, but I think he's the only one, and several others removed them.

One other point, one or two owners found the fan blade was installed backwards...so at least check that.

[ipd]

Main fan spins about 1/2 turn after i spin it.

[ipd]

Took it out today for some small trips, stop & go, etc. Came up to middle temp range VERY fast, but stayed there--didn't budge. Even with A/C on full blast, didn't move from center. I dunno. Wife thinks the trip across the desert yesterday. Taking it to a shop for a full shakedown this week, hopefully.

Thanks for the help so far.

[Triathlete]

Mine was overheating in stop and go traffic and at slow speeds down here in Tucson. I replaced the fan clutch last week with a new one from autozone. No more overheating issues. Easy 30 minute job with basic tools.

[ipd]

Had the coolant flushed today & the fan clutch replaced. No issues yet. Knock on wood.

[ipd]

Well it seems I'm back to square one. Overflow tank is boiling again. Was only bubbling sometimes, but steam was coming out of it tonight when I parked it. Drove fine from AZ up to UT without issue. Had an oil change & I think they may have added coolant in the process. I'm really not sure what's causing it though. Oil level still reads fine. I'm at my wits end.

[Y33TREKker]

Well it seems I'm back to square one. Overflow tank is boiling again. Was only bubbling sometimes, but steam was coming out of it tonight when I parked it. Drove fine from AZ up to UT without issue. Had an oil change & I think they may have added coolant in the process. I'm really not sure what's causing it though. Oil level still reads fine. I'm at my wits end.

Have you ever changed your radiator cap? The purpose of a properly operating cap is to increase the pressure in the radiator/cooling system to allow the coolant to reach it's designed boiling point.

What is your coolant level in the radiator itself with the radiator cap off and the engine running at normal operating temps (the coolant/engine hot enough to open the thermostat)? It should be up near the top of the tank when looking into the radiator cap opening. I wouldn't just trust what the reservoir level is telling you anyway since you may have an air pocket elsewhere in the engine.

You could also try adding the aftermarket product Water Wetter. It increases the surface tension of whatever coolant you're running, effectively increasing it's boiling point.

I'd have my doubts that you have a head gasket issue if the engine so far has been running evenly, but you could always have your cooling system pressure checked (with one of the gauges that installs where the radiator cap usually goes) to determine if you have any air leaks in the cooling system.

[ipd]

Just got off the phone with the shop. They said they could find NOTHING amiss, apart from air in the coolant system--which they bled out. Given that the car ran just fine from Phoenix to SLC--no temp issues--I can only assume that it must have stemmed from the quickie-lube shop cracking the cap on the radiator to "fill er up". I'm still new to the VX. Is this engine an odd type of configuration that requires special handling to prevent air from entering the coolant system?

For the record, the Head Gasket was replaced about 1k prior to me buying this VX, and the Cap was replaced & the coolant was flushed--back in Phoenix.

This is the 2nd time I've been told--since arriving in SLC--that the coolant was low. Once by the quickie lube place who poured coolant directly into the radiator (I didn't see them doing it until it was already underway), and once by the shop who bled the system. What I'm confused on is whether I actually have a leak or not. If I have a leak, then that would explain the coolant being "low" but not why I was able to drive it successfully for 12+ hours of road travel without issues (because a leak would mean I couldn't pressurize the system, and therefore would overheat).

[Y33TREKker]

Just got off the phone with the shop. They said they could find NOTHING amiss, apart from air in the coolant system--which they bled out. Given that the car ran just fine from Phoenix to SLC--no temp issues--I can only assume that it must have stemmed from the quickie-lube shop cracking the cap on the radiator to "fill er up". I'm still new to the VX. Is this engine an odd type of configuration that requires special handling to prevent air from entering the coolant system?

For the record, the Head Gasket was replaced about 1k prior to me buying this VX, and the Cap was replaced & the coolant was flushed--back in Phoenix.

This is the 2nd time I've been told--since arriving in SLC--that the coolant was low. Once by the quickie lube place who poured coolant directly into the radiator (I didn't see them doing it until it was already underway), and once by the shop who bled the system. What I'm confused on is whether I actually have a leak or not. If I have a leak, then that would explain the coolant being "low" but not why I was able to drive it successfully for 12+ hours of road travel without issues (because a leak would mean I couldn't pressurize the system, and therefore would overheat).

It could just be that with an air pocket in the system, an accurate reading from the reservoir couldn't be determined. This is referred to in the following procedure from the VX manual.



It also has to be remembered that the transmission cooling is handled by the trans line coils in the radiator, so if you're pushing the VX/transmission hard, that puts more cooling load on the radiator besides just the heat being generated by the engine.