FYI for those people with overheating issues with their VX

[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.

[ipd]

Took it out for a long drive today. Not one issue. I've been researching this even more, and it appears to be a fairly common problem caused by idiot mechanics doing similar "top off" things. I've never had this type of issue with my other vehicles, so I'll be keeping a hawkish eye on it to make sure no 2-bit mechanic pops open the radiator cap. Ever.

[Y33TREKker]

Took it out for a long drive today. Not one issue. I've been researching this even more, and it appears to be a fairly common problem caused by idiot mechanics doing similar "top off" things. I've never had this type of issue with my other vehicles, so I'll be keeping a hawkish eye on it to make sure no 2-bit mechanic pops open the radiator cap. Ever.

If I had to guess, I'd say that any overfilling by such mechanics takes place just because they are under so much pressure to get the job done so fast, so they pour as much in as fast as they can.

Some vehicle manufacturers account for the possibility by having a plug in the thermostat housing that can be removed to allow air to escape during the filling process, although my daily driver even has a second "radiator" cap near the thermostat housing that allows me to open the system there to let air escape and add coolant once the car has been running for a few minutes and the thermostat has opened.

Unfortunately, the VX's cooling system has neither of those options, so you just have to do it old school and do all of the coolant filling and top-offs at the radiator inlet itself.

The key is to let the engine get to operating temps (hot enough that the thermostat has opened and coolant is flowing from the engine to the radiator), observe the level of the coolant in the radiator inlet, and add accordingly at that point.

[ipd]

Final update....hopefully.

Had the head gasket replaced. According to the Mx receipts from the previous owner/s, the head gasket was done previously--but it might not have been done up to snuff. 2 different shops confirmed hydrocarbons in the coolant--so it was a sure thing. Water pump is in pristine condition, which is evidence that it had been changed recently. Biggest question-mark was the head bolts, as the shop indicated that these had apparently stretched. It is not known if these were pushed by head gasket pressure, or if they were faulty previously and not replaced during the last attempt at this repair. It does come with a 12 month 12,000 warranty, so I expect to be driving the piss out of it this summer with the A/C on full blast--just to "stress-test" it to verify that I'm not still getting issues with it. (Hard to tell when I'm doing 15-20m trips and it's 15 F outside).

I'll also be religiously checking my oil levels, as I may now start to see oil consumption (although I noted none previously). What still unsolved is how I got it from SD to Phoenix and finally to SLC without having a catastrophic breakdown.

[Y33TREKker]

Glad to hear the of the more detailed diagnosis and that the issue is, hopefully, resolved.

I'm sure the new head gaskets and head bolts will help and offer more peace of mind.

[eternal21]

Got the new fan clutch, fan blade and thermostat installed.
Merlin advised a redesigned OEM fan clutch is the only one available now, and requires a new fan blade as well. New fan clutch is now $250 and blade $100... OUCH! Old fc was around $70 IIRC....

If you order this part from Isuzuparts.com, you need to specify the part number. If you have the new fan clutch (part number 8-97349-761-0) DO NOT order online as they will send you the old fan (part number 8-97172-201-0, bottom picture above). When I had to call them after ordering online because they sent me the wrong fan, the guy I spoke to (Brian) said that the new fan doesn't even show as a part for the VehiCROSS. Just as an FYI, the redesigned fan part number is 8-97349-762-0, top picture above).

The old fan/new fan clutch are physically incompatible.

[Nikad92397]

Seems to me that there is another problem.
People have tried all sizes of radiators,
All sizes of fans, all kinds of combinations of ideas and they all point to one thing. Air flow.
Hood scoops help, stock or updated clutch and fans work. Everything else should help but it doesn't.

I was out in Barstow a few weeks ago and in deep sand washes littered with rocks I started getting to the
Big H on my gauge. It was 112 degrees out and who knows how hot in the washes (yes my A/C was on)
I sped and put it in park and just sat there with my foot holding the gas peddle to a fast idle and it cooled down to just before half way on the gauge. Sounding like a airplane stuck in the mud, A/C still on.

I kept thinking of all these posts and my brain kept coming up with air flow. I couldn't cut the hood in nowhere land, couldn't check all there other things out in the bush so I pulled the grill off, my temp never left 1/2 way on my gauge for the rest of the day, air flow. Hummmm. Anyone else ever pull their grill off and try it ? Worked for me so I made a summer grill.
Seems to be working.

[Nikad92397]