overheating is back

[tom4bren]

I do have a scan guage ... but it's in the RV. Last time I hooked it up in the 'Clips, it turned off my speedo. Wierdest thing I ever saw. I'll give it a shot though, now that the hot weather is here, it may give some interesting results.

[Triathlete]

Do you have a ScanGauge, or some other OBDII reader that you can hook up to the car (either of you)? That way you could get a temp reading off the ScanGauge and bypass the dash gauge to see if it is reading correctly or not.

But, if the sensor is bad the scan gauge will still give a bad reading since the scan gauge will still be getting its signal from the bad temp sensor.

[MSHardeman]

But, if the sensor is bad the scan gauge will still give a bad reading since the scan gauge will still be getting its signal from the bad temp sensor.

Very true Billy. Didn't pay attention (nothing new there) to the fact that we were talking about the sensor and not the gauge itself. If just the gauge is bad then the ScanGauge will read correctly if the sensor is bad then everything will be all cattywhumpus.

[tom4bren]

But, if the sensor is bad the scan gauge will still give a bad reading since the scan gauge will still be getting its signal from the bad temp sensor.

I'm thinking the sensor that turns the fan on/off (not the sensor for the guage). When the AC is on, the temp is rock solid where it's supposed to be. I got the sensor from the stealership but it looked different (not as long). There has to be a reason that a longer probe is better!!!

[zadam123]

also as far as the block tester I did have a mechanic stick in old emissions tester ( the 1 used for your tail pipe) into the radiator reservoir tank and it did show a little co2 there. but no other mechanic has ever heard of this test. it seems like the same idea it is just that every mechanic is telling me it is not a head gasket. it is so hard to find a good mechanic

[Y33TREKker]

also as far as the block tester I did have a mechanic stick in old emissions tester ( the 1 used for your tail pipe) into the radiator reservoir tank and it did show a little co2 there. but no other mechanic has ever heard of this test. it seems like the same idea it is just that every mechanic is telling me it is not a head gasket. it is so hard to find a good mechanic

Along the same line then, could you do something like a compression test on that front, passenger-side cylinder to see if air bubbles end up in your radiator or reservoir tank? When looking for blown head-gaskets, I know that bubbles in the radiator are what some look for when the engine is running, but it seems like differentiating between bubbles caused by basic water flow through the engine and/or the thermostat opening and closing would be guesswork at best.

Pressurizing the cylinder chamber with the engine cold, then hot (but not running) would be an additional way to determine if pressure leakage due to heat expansion were affecting things in any way.

Just trying to throw some possibilities out there.

[rsteinmetz70112]

I thought were were talking about both and the wiring in between.

[zadam123]

It seems like the thermostat is still on order, he said he did a compression test and that was fine but he is going to get that block tester and try that befor he does the thermostat.

will keep you guys posted

thanks for all the help

[phines]

Your VX should not be overheating with the 170 degree thermostat (unless it's broken). That's what I have in mine now... That was one of the many things I tried when mine was overheating but it didn't make a difference.

[VXobsession]

I've replaced my fan clutch, wasn't working. Thought it would be the relay but it was the fan itself. Fixed my head gaskets. Still running warm sometimes, like up to the 3/4 mark, but then it goes back down. I've noticed the fan doesn't come on until then. Never gets up to the hot mark anymore. Do these things normally run this warm? I've only had her a month, so I'm not used to her characteristics. I live in northern Arkansas and temps right now are sometimes over 100 degrees.

[zadam123]

I've replaced my fan clutch, wasn't working. Thought it would be the relay but it was the fan itself. Fixed my head gaskets. Still running warm sometimes, like up to the 3/4 mark, but then it goes back down. I've noticed the fan doesn't come on until then. Never gets up to the hot mark anymore. Do these things normally run this warm? I've only had her a month, so I'm not used to her characteristics. I live in northern Arkansas and temps right now are sometimes over 100 degrees.

had mine since new and always rand between 1/4 -1/2

[zadam123]

OK here is where i am at . last i told you the mechanic said he checked the bolt and it was fine (I hope he checked it) He said he did a compression test and it was fine (again was not there so taking him for his word) he said it was absolutaly the thermostat being aftermarket so it told him about a compression leak tester that changes the blue liquid to yellow if there are gasses in the radiator to make it overheat (kind of on the same basis as the emmisions in the overflow for the antifreeze which my car failed detecting the co2) he said he would get one and test my car befor he did the thermostat.

so he got one and tested it and told me it was fine and the thermostate was the problem so i got one from st charles since for 2 weeks my mechanic said it would be there tommorrow, +1 for st charles got mine in 3 days. well after him putting it in he told me he took my car on a test drive and it was fine, good to go. great i thought untill i took if for my test drive an guess what , you got it . it OVERHEATED AGAIN!!

I went to autozone and got my own engine compression leak tester and sure enough it passed on this one. here is a pick and video of the blocktester and how it was used.



here is the video of the test and results

http://www.youtube.com/watch?v=X05PDw5IE1U


Here is the thing, I told the mechanic to get my car to over heat you have to drive it hard, meaning reve it above 3000 rpms. maby floor it a few times all when driving on the highway. for example I live in staten island , i took my car on the expressway for roughly 15-20 miles not to much traffic , I drive it around 50-70 mph moving the revs around from 2000-5000 . doing this the temp got right to the hot line at the end of this drive about a 15 - 20 minute ride. going back home i babied the car only going 40 and keepiing the revs at 2000 not above and the temp stayed at the line below the h but never rose.

any ideas, im at my whitz end, i really dont want to get rid of the vx but cant keep fixing things that dont solve the problem.
could it be the bolt if there are no gasses in the radiator?

[Triathlete]

An overheating tranny will cause overheating. Also have you had your radiator flow tested?

[Bob Barker]

I would imagine if you modify your driving habits then your vehicle would no longer overheat. If you have to drive at 5k RPM for 15-20 minutes then just don't drive like that and it wouldn't give you issues. I don't ever need to drive my VX like that, even when I'm goofing off in the dirt.

I'm sure the factory system should be strong enough to cool the engine under hard driving, but extreme driving for 20 minutes would put almost any factory stock cooling system to the test, and repeating that would eventually cause parts to fail.

[zadam123]

I would imagine if you modify your driving habits then your vehicle would no longer overheat. If you have to drive at 5k RPM for 15-20 minutes then just don't drive like that and it wouldn't give you issues. I don't ever need to drive my VX like that, even when I'm goofing off in the dirt.

I'm sure the factory system should be strong enough to cool the engine under hard driving, but extreme driving for 20 minutes would put almost any factory stock cooling system to the test, and repeating that would eventually cause parts to fail.

i did that just to see if i still over heated. if I drive on long distance on an expressway at posted speed I will still overheat. it just happens faster if I drive a little harder. the drive was mostaly at 3000 rpm but passing vehicles was at the 5roll mark