89 Nissan 240sx overheating sometimes.

[excelscior]

I have a 89 240 sx. It has 150k miles on it. I have owned it for the last 7-8 years. I drive about 4500 miles a year approx, but not more then 5k. I live about 5 minutes to everywhere I need to go too. I had the radiator and thermostat replaced 2 months ago. I have heating issues about 5 minutes into driving. My thermostat is at normal operating temps most of the time. sometimes ( mostly at night or early morning 6am ) 5 minutes into the 10 minute trip my gauge will go over the half way mark. It will come down back to normal but it will sometimes fluctuate between higher temps and normal. This rarely occurs when it is hot outside and I am idle in traffic. This usually only occurs when I go to work early or need to pick something up late nite at the store. The only thing I have not changed is the water pump. Water seems to be circulating and I dont see coolant missing or see any leaks. Is the water pump that important where it can effect the temperature that extreme? I want to keep the car because it runs well. But mostly because I don't drive enough to justify buying another car just yet. The car would be parked more then driven if I did. Any suggestions as what it could be maybe? I don't have any problems with volume or have to replace coolant often. thanks in advance for any suggestions. Bye for now.

[Lgbpop]

It's just the way your car warms up. When cold the thermostat is shut and the fan doesn't sense enough heat to run. Once the thermostat opens, all the hot coolant from the block heads for the radiator and it takes several seconds for the radiator fan thermosensor to turn the fan on. Until it does, it looks like the car's running hot. Nothing unusual.

[excelscior]

I would take that as sound advice. But the problem is that this had never occured before in the 7-8 years I have owned the car. Just this past year, 3 months to be exact. Logically it also makes sense what you say. I just can not explain why all of a sudden this overheating issue has occured. I know the car is 20 years old now. I just do not think it is ready for retirement. Mechanics I have asked tell me the OEM Nissan 240sx engines can go 250k miles easily. I hope this is the case with mine. I have tried taking care if it with regular oil changes.

[j.m@talk]

It may have a wee bitta air in the cooling circuit. Get a Nissan/Infiniti Tech to have a quick twiddle ..... Certainly not a biggie

[j.m@talk]

Excelscior sets off to do a lil kerb crawling



Shoulda bought a right hand drive fer that

[Lgbpop]

I wouldn't worry about the engine. Have the radiator flushed under moderate pressure (reverse-flushing isn't what it's cracked up to be, avoid it) and then check for proper fluid flow through it. I bet after almost 20 years it's gotten a bit clogged. If necessary replace the radiator.

[j.m@talk]

I wouldn't worry about the engine. Have the radiator flushed under moderate pressure (reverse-flushing isn't what it's cracked up to be, avoid it) and then check for proper fluid flow through it. I bet after almost 20 years it's gotten a bit clogged. If necessary replace the radiator.

You can't read ........

[leprechaun_40]

You either have an air bubble in the cooling system or maybe the block needs flushed. Also, how about that temp sensor, it's old, could be it's flaky.

[athlonfan]

What I can't figure out, and what I haven't seen anybody else explain, is why he doesn't have this problem in traffic.

[Lgbpop]

The engine is always hot enough in traffic to keep the fan on all the time, so the temp is warm but consistent. Only when it's cool enough (for whatever reason) for the fan to cycle on and off will he get the temp fluctuation.

[leprechaun_40]

Needs to stick an accurate thermometer in the radiatior and run the engine around 2000 rpm until the fan comes on and watch the temps.

[excelscior]

So far so cooled as I see it. I been doing the usual stop and go driving to work and pick-up my little one. I changed the oil again ( Mobil 1 type 0-30wt ) and it seems ok for the moment. I will have the mechanic replace the water pump soon. The car has 150k on it and the mechanic says at 175k it will need a new timing belt. Maybe I will have him do both jobs now instead of later. For now no over heating issues. I did make sure the coolant resevior hose was unclogged. well see how long this last as far as constant temps. Thank goodness I don't need to drive the freeways or I would need to replace the car for sure. Thanks again.

[Lgbpop]

Thank goodness I don't need to drive the freeways or I would need to replace the car for sure.

I'd rather walk than drive 405. We did that for a week on vacation several years ago, never again.

[j.m@talk]

I'd rather walk than drive 405. We did that for a week on vacation several years ago, never again.

Woo yeah ...... Thats the trouble with roadz these days ..... "Other Cars" have the audacity to use them too..... Wouldn't of happened in my day ..... Fwoar noooo sireeee! ... I tells ya ..... When I was in the Blahh blahs, Blahin' the blahs .... & all of a sudden Wibbley wobbley

[mireland]

Woo yeah ...... Thats the trouble with roadz these days ..... "Other Cars" have the audacity to use them too..... Wouldn't of happened in my day ..... Fwoar noooo sireeee! ... I tells ya ..... When I was in the Blahh blahs, Blahin' the blahs .... & all of a sudden Wibbley wobbley

ahhh..there's that subtlety you were mentioning earlier...