Car Running HOT, NOW WHAT?

I purchased a 94 VW Golf Diesel a few months ago and it has been running great, except for the fact that it has been running hot. When I first got the car the temp gauge did not work so I replaced all of the temp sensors in the RAD and water jackets, three in all. This got the RAD fan and temp gauge working properly. BUT the car was still running at 110 F when it should be running around 90 F so I replaced the thermostat on the weekend and took the car out for a trip, it's still running around 100 - 115 F, when I had the thermostat out I inspected the water pump and it looks great and moves freely. WHAT AM I MISSING?

Reply to
HotRod
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first of all those temps are C not F...

secondly, where are you reading this temperature? From the gauge or from the MFA (digital display) if you are reading this from the MFA that is oil temp not water temp and 110C is no cause for alarm. I can't honestly remember if the A3s had the water temp gauge calibrated in degrees or not; I know my A1s and A2s did not, I always thought that was a little cheezy. Anyway if your oil temps are just a little over

100C that is about perfect.

nate

Reply to
N8N

Well maybe I have this all wrong. The sensors I replaced were in the RAD hoses and RAD so assume these are water Temperatures. Also does anyone know whether the Temp. gauge on a 94 golf is oil or water? And since this is a Canadian Car is the F or C....

Like I said the car seems to be running fine but I think the temp gauge is a little high?

Other QUESTION when I refilled the RAD is there a bleeder screw that I need to bleed the air out, just like my late model Porsche 924 which was also VW???

Reply to
HotRod

I have almost the same car, and it runs with the temp needle vertical. Every time it has run hotter that that it was air in the system. Its quite difficult to bleed, but almost always seem to bleed itself after a couple of days....

Maybe just need to be patient?

Reply to
Eduardo K.

I'm still confused... do A3 temp gauges actually read in degrees? still not clear (to me) where he's getting these temp readings from, i.e. is there even a problem

anyway the best way I have found to fill a VW engine is to remove the upper rad hose, and fill through that... then fill the radiator as well... (use a flexible funnel) then there won't be an air pocket around the thermostat and it will open as soon as the engine gets hot and burp the rest of the air up to the bottle.

nate

Reply to
N8N

In addition to the other comments, see PRESSURIZED BOILING POINTS OF GLYCOL SOLUTIONS on

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I can't verify their numbers, but they sound right.

The points you are missing is that, while pure water boils at 100 Celsius at sea level atmospheric pressure, when you pressurize the radiator, you get higher boiling points.

Using a 50% ... 60% ethylene glycol antifreeze also raises the boiling point. (choosing the right antifreeze and using distilled water is a whole different discussion).

If you are not losing coolant when things read hot, don't worry about it. Hotter is good to a point.

Reply to
Tom's VR6

I haven't lost any coolant at all and can't say that I've noticed any boiling. I am using a 50% antifreeze to water mix. I'm just afraid that the engine is running to hot it always seems to run at the 110. I prefer the heat in the winter but not the summer.

Reply to
HotRod

OK here's the update. And NO I haven't touched anything else since I last posted (Haven't had time). This morning when my wife took the car to work it got to 120 C and the warning lights came on, she was able to let it cool down and then ran the heater in the car all the way back to the house (about

10 min.)

I'm going to try re-filling the RAD and try to bleed out any air pockets.

Reply to
HotRod

Maybe the warning light is indicating low oil pressure rather than excessive coolant temperature. If that is the case, perhaps you need a new oil pump. Just a thought.

Reply to
Papa

yes. non-US ones read Celcius. 90 is just the middle position and both my A3 Golfs read that always.

yes. I do that and it works quite well, although mos of the time the first time around it goes up to 100degrees and then drop to 90 as soon as the air bleeds.

Reply to
Eduardo K.

Last night I pulled the big RAD hose off of the top of the engine and stuck a hose in both the engine and RAD to make sure everything was full. I also tested my RAD fan switch and it appears to be working fine. After the top up I loosened the cap on the bottle so that the system could burp. Anyway the temp gauge still hit 115 C before I shut it down.. Before I pull the thermostat back out are there any other suggestions on how to get air out of the system or anything else to try????

Reply to
HotRod

warning: dangerous!

-fill up.

-install cap

-start car

-let it warm

-loosen clamp on top hose, let air escape, tighten clamp.

-cool down 2 hours

-repeat until no more air comes out...

Reply to
Eduardo K.

I pulled the thermostat last night and filled the car up with water and let it run. THe car ran nice and cool except for the fact that without the thermostat in the housing was leaking. I'm going to try a different thermostat since when I tested this one in the house it wouldn't even open until 110 C.

Reply to
HotRod

HUH! that doesnt sound right... should be mid-high 90s

I guess sometimes it is the simple, stupid stuff.

nate

Reply to
N8N

I'm going to install a new thermostat tonight and see if that makes a difference. Believe it or not I can now drop the power steering and remove and re-install everything in about 30 minutes. I think it takes longer to clean up the tools. I love how easy it is to work on this car.

Reply to
HotRod

OK I've installed a new thermostat this weekend and made sure to test if before I put it into the car, it seems to be working fine, BUT the car is still running hot 110+, I've followed the steps of warming the car to 110 and then loosening the cap to let the air out and then letting the car cool down and starting over. I've done this about 6 times and it still doesn't seem to be running any cooler. Any other ways to get the air locks out?

Once again I inspected the water pump and it seems to be fine.

Reply to
HotRod

I going to say something that sounds daft, but I`ve done it and it works. I run a MK2 Golf Gti, quite highly tuned. At one stage it even melted a series of exhaust manifolds! My water temperature used to get silly high too. So much so it regularly blew the expansion bottle. One day when I was in a motor factors I discovered that there are several thermostats with different opening thresholds. I chose one that opened very early, 80+, and do you know, from that time on even stranded on the M25, in a traffic jam, the old engine runs happily just a shade on the cool side. Please keep us up to date with your progress.

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Reply to
tonyelkins

At one point I pulled the thermostat out of the car and ran it for a few days without the thermostat and it ran nice and cool. Except for the fact that I had to keep topping up the coolant because the housing wouldn't seal properly without the thermostat and O Ring. I've considered drilling 90% of the centre out of the old thermostat and then reinstalling it to see how that holds up. I just can't figure out why it's running so hot with a new thermostat.

Reply to
HotRod

housing together. As to thermostats. There are choices for the retailer. But to stock multiples of each costs money and in these inlightened days this represents capital lockup on potentially slow moving items. I would not advise removing the themostat. As well as regulating temperature it also regulates flow pressure and might provide the water pump with more work than it may be happy to handle long term. Also, and I do not know what your winters are like, but on a cold moning it takes a long time for the interior to warm up. Just take a relaxed toddle round to a spare parts dealer, preferably not VW, and see what the options are. I am almost certain you will be pleased that you did. If you do`nt have any luck drop me a line and I`ll see if I can get one to you.

Reply to
tonyelkins

Any recommendations on what temp. I should look at? I'm assuming I'm only changing the temp that it opens at?

Reply to
HotRod

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