Ok, I am paranoid. The only other car I ever had a head gasket fail was a 84 Corolla. Now my 90 is running above the middle. I have changed the thermostat with a Toyota stock thermostat, coolant and radiator cap. I am still running at the middle or a little above. My fan comes on right at 199F which is what it is supposed to do. Is this normal? Should I worry about this? All the cars I have had in the past, the gauge runs right at the middle. Also, never had a car run the fan so much. There is no sign of a blown head gasket that I can tell. So am I just being parinoid?
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Pat Callaghan
90 Corolla DX
Portland, OR.
Sounds like its running too hot to me, mine stays about 1/4 to 1/2 up the gauge, no more, unless im just idling. I don't have any sort of cooling fan either though so thats my idle problem.
It could be the gauge itself that is slightly off. When I did my cluster, the temp gauge on the old cluster would go up almost 3/4 before the fan kicked in to bring it down to the mid-point. The LE cluster I have now, the temp gauge never went higher than mid-point at given time.
What kind of coolant did you put in? Maybe the mixture was off... 50/50 ideally.
If your fan comes on when it's suppose to at least and cools it down, you should be fine.
Head gasket failures would either involve misfires between cylinders and/ or engine oil present in the coolant or vice versa. Which would lead to overheating since the coolant is now milkshaky oil shit.
Thanks for the response. There is no coolant loss or oil/coolant contamination. The fan comes on at exactly 200F according to my candy thermometer I tested the fan with. The coolant is at least 50/50. Maybe 60/40. I used Peak longlife coolant. I guess I will just keep an eye on it.
Quote:
Originally Posted by SCT
It could be the gauge itself that is slightly off. When I did my cluster, the temp gauge on the old cluster would go up almost 3/4 before the fan kicked in to bring it down to the mid-point. The LE cluster I have now, the temp gauge never went higher than mid-point at given time.
What kind of coolant did you put in? Maybe the mixture was off... 50/50 ideally.
If your fan comes on when it's suppose to at least and cools it down, you should be fine.
Head gasket failures would either involve misfires between cylinders and/ or engine oil present in the coolant or vice versa. Which would lead to overheating since the coolant is now milkshaky oil shit.
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Pat Callaghan
90 Corolla DX
Portland, OR.
If you need a new radiator, you can get them cheap on eBay and they are decent ones too. Easy to replace. Hey, they don't last forever, almost, but not quite...
The temp gauge should be slightly BELOW the 1/2 point on the dial (= a coolant temp of 180 degrees F) during routine driving and the fan should stay off as long as the car is moving. But when idling at a long stoplight the gauge needle should rise to the 1/2 point (coolant temp 199 degrees) and then the fan should come on for a minute or two and lower the gauge to slightly below the 1/2 point again. This process will keep repeating itself as long as the car is stopped and idling.
It is possible your gauge needle is slightly off calibration if the gauge reads slightly above the 1/2 mark when the fan first comes on as along as the needle returns to the 1/2 mark when the fan shuts off.
Or, the reason your gauge is always at the 1/2 to 2/3rds mark might be because you installed a 190 degree Toyota thermostat instead of a 180. The correct 180 thermostat to use is Toyota part number
90916-03046 and the correct Toyota thermostat gasket is 16325-63010. Sometimes even using the wrong thermostat gasket will cause higher than normal temp gauge readings.
Another very common cause of temp gauge readings higher than the 1/2 mark on an older front wheel drive Corollas is partially clogged INTERNAL core tubes inside the radiator due to years of using aftermarket coolants and / or tap water. These core tubes can't be fully cleaned using cleaners or rodding the radiator so the radiator has to be replaced. Using Toyota coolant and distilled water prevents this internal radiator clogging from ever occurring. The Koyo (Japan made) radiators on ebay are good quality replacement radiators.
Still another potential cause of higher than normal temp gauge readings is under or overadvanced ignition timing or a slightly low coolant level in the radiator.
The integrity of the head gasket is not jeopardized unless coolant temp gauge readings go up to the
3/4 mark or beyond or if the owner runs the car real low on coolant in which case the temp gauge sensor may not be immersed in coolant and so the gauge never registers overheating when in fact overheating is occuring.
The thermostat is the correct part numbers. The timing is at 10BTDC which is what is called out. I can't really verify the others unless I just start replacing components. Thanks for the info.
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Pat Callaghan
90 Corolla DX
Portland, OR.
Sounds to me it would be your temp guage itself...i dont think the stock dx cluster seems all that reliable IMO. i know mine messed up and i got an LE cluster. But we have that covered so i wouldnt panic for now.
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1994 Acura Integra RS (DC4)
1985 Toyota MR2 MKI-A
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