Help Engine overheating, and wipers not working.
11-08-2009, 07:04 PM
#11
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Lets look at your picture:
I'm not all that familiar with the 90's, but I can tell several things from your photo.
The main object in the foreground (big silver object with the number '5' and the clip in it side) is your engine temperature sensor. It sends the information directly to your temperature gauge.
the "small woven cloth covered tube that splits into a y" is actually a pair of electrical wires and I very much doubt they'll be the source of your hissing!
I can't quite tell, but the aluminium tubes running underneath the temp sensor look like part of the aircon system. Did you have your aircon running during your test drive?
What I would suggest is this:
The thermofans operate via an independent switch which should be located in the radiator. The fact that they are coming on then turning off tells me that they are probably working properly.
The hissing noise could be one of two things:
1. If you do indeed have an airlock in your cooling system, the hissing noise could be the hot air under pressure behind the engine temp sensor pushing past the o-ring seal - this would definitely explain your sky-rocketing temp reading & isn't good for the engine - it needs to be bled straight away (I'm sure there's a tech article on here somewhere... You normally bleed through one of the heater hoses). Vapor-lock also explains your coolant blowing out from your reservoir when under pressure.
2. If your aircon was on, it could simply be the pressure equalisation in the tubes after shutdown (Audi's use an orifice tube in place of a TX valve, so the pressures on both sides of the aircon system equalise almost immediately once the compressor stops).
If the Aircon was the source of the hissing sound, and the cooling system does not need bleeding I would definately suspect the Thermostat. If it is trapped shut, your car will not cool properly and the thermofan operation could also be a result of the aircon triggering it. Though with your heater working properly, I don't think your thermostat is the problem...
As for the car running rich, solve your overheat problem first. The temp sensor may be operating outside the ECU's accepted range, and this could be causing your fuel system to operate in closed loop (safe setting). Check it out once you're no longer running hot!
I'm not all that familiar with the 90's, but I can tell several things from your photo.
The main object in the foreground (big silver object with the number '5' and the clip in it side) is your engine temperature sensor. It sends the information directly to your temperature gauge.
the "small woven cloth covered tube that splits into a y" is actually a pair of electrical wires and I very much doubt they'll be the source of your hissing!
I can't quite tell, but the aluminium tubes running underneath the temp sensor look like part of the aircon system. Did you have your aircon running during your test drive?
What I would suggest is this:
The thermofans operate via an independent switch which should be located in the radiator. The fact that they are coming on then turning off tells me that they are probably working properly.
The hissing noise could be one of two things:
1. If you do indeed have an airlock in your cooling system, the hissing noise could be the hot air under pressure behind the engine temp sensor pushing past the o-ring seal - this would definitely explain your sky-rocketing temp reading & isn't good for the engine - it needs to be bled straight away (I'm sure there's a tech article on here somewhere... You normally bleed through one of the heater hoses). Vapor-lock also explains your coolant blowing out from your reservoir when under pressure.
2. If your aircon was on, it could simply be the pressure equalisation in the tubes after shutdown (Audi's use an orifice tube in place of a TX valve, so the pressures on both sides of the aircon system equalise almost immediately once the compressor stops).
If the Aircon was the source of the hissing sound, and the cooling system does not need bleeding I would definately suspect the Thermostat. If it is trapped shut, your car will not cool properly and the thermofan operation could also be a result of the aircon triggering it. Though with your heater working properly, I don't think your thermostat is the problem...
As for the car running rich, solve your overheat problem first. The temp sensor may be operating outside the ECU's accepted range, and this could be causing your fuel system to operate in closed loop (safe setting). Check it out once you're no longer running hot!
11-08-2009, 07:33 PM
#14
AudiWorld Super User
what u c as #5 is a fuel pressure regulator!
those braided lines, are vacuum lines, they are not the source of overheating, but the dont help. and yeas they are the source of hisssssing...
because the fans are coming on and shutting off means that they are NOT working properly, because the fans are supposed to help with cooling of the car. If they come on at a certain temperature and then turn off as the temperature keeps rising, whats the point of them then? ;-)
btw, r u using G12 or G11 coolant?
those braided lines, are vacuum lines, they are not the source of overheating, but the dont help. and yeas they are the source of hisssssing...
because the fans are coming on and shutting off means that they are NOT working properly, because the fans are supposed to help with cooling of the car. If they come on at a certain temperature and then turn off as the temperature keeps rising, whats the point of them then? ;-)
btw, r u using G12 or G11 coolant?
11-08-2009, 09:22 PM
#15
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Vacuum leak could still be causing the running rich problem.
Green coolant means its not G12, which is red.
OK... Am I right in that the 80/90 12v's run a thermoswitch in the radiator? If so bypass it & see if it still overheats.
11-08-2009, 11:43 PM
#16
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Alright, so I did some more test driving, the engine does seam to cool down if I go about 40 MPH and keep the revs low, I know the fans are not coming on. How hard would it be to replace the thermoswitch? Thanks again everyone, your efforts are greatly appreciated.
11-09-2009, 08:19 AM
#17
AudiWorld Super User
nope, wrong. the thermostat is on the block behind the t-belt.
http://12v.org/engine/index.php?section=cl&view=cool
btw, if u c a car with a thermostat in a radiator, let me know please ;-)
i was asking what coolant he was running, not you!
so you fans are capoooot, try testing your fan switch (bottom driver side of the radiator, i think) also just spin you fans by hand and c if they turn (car off when u do that) they may have locked up. also, get a volt meter
http://12v.org/engine/index.php?section=cl&view=cool
btw, if u c a car with a thermostat in a radiator, let me know please ;-)
i was asking what coolant he was running, not you!
so you fans are capoooot, try testing your fan switch (bottom driver side of the radiator, i think) also just spin you fans by hand and c if they turn (car off when u do that) they may have locked up. also, get a volt meter
11-10-2009, 11:42 AM
#18
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update
Well, although I love this car, unfortunately there are some more major issues popping up. Turns out all the valve guides and seals are gone. Started smoking really bad. The guy I bought it off is being pretty nice, he understands he did not sell it properly. If I cant get money back, I am going to part it off or sell whole for you guys. On a side note, a person I have dealt with before, has a sweet v8 Audi he may sell me, this could happen very soon! I believe it has somewhere around 66,000 miles, and is absolutely pristine. He is German also ;-)