overheating pls help

[89240sx]

ok here's the story.... My car was overheating when stuck in traffic for too long if I started to drive the temp gauge would go back down.

It seems now its overheating more often, tomorrow i'm going to flush the coolant and change the radiator cap and thermostat unsure what the problem is when I got to work today i heard a sound which was the water in the plastic reservoir boiling and a slight hiss from the radiator cap but I wasnt HOT HOT i was alot hotter than normal but not on HOT (probably 3/4 up on the gauge) ,

I put about a quarter of a gallon of water in the radiator and capped it off. What do you suggest besides thermostat and flush and radiator cap? There are no leaks that I can find and a quarter of a gallon isnt really that much if there is a leak. One more question ... How do I test the fan clutch? I have an 89 240sx ka24e

Any help would be greatly appreciated because I HAVE to be able to get to work =)

TIA

Mark

[89240sx]

Ok here is an update, I got a chance to look at it closer today...

There is no coolant in the oil but there is a leak! and when you look underneath the leak looks like it is coming from the oil pan gasket in the front portion of the engine... something that was peculiar is that there is red form a gasket across the front of the pan where someone "patched" that area.

Now I know this makes no sense that there is no coolant in the oil and it looks like it is leaking from inbetween the front of the oil pan and block ... I'm at a complete loss

Also here are the compression test results:

1-------------2-----------3----------4160-170 150-160 150-160 150-160

those are the ranges of the results that I got when compression testing

There are 141k miles on the engine.

Any help would be greatly appreciated

(tomorrow i'm cleaning the bottom and front of the block and oil pan at the car was to better see everything and I changed the oil to double check the water in oil theory, after changing the oil I drove about 60 miles and checked oil and no water or coolant in oil)

The car uses around a quarter to a half of a gallon of water every other day (rough estimate)

TIA

Mark

[p00t]

definately sounds like the water pump is dead and/or not sealed right.

the water pump is in the front of the engine, it is driven off of the same assembly that drives the mechanical fan. infact the same pully that drives the fan is what powers the water pump.

my theory of what happened is that the pump was on its way out, and you kept driving with it like that (you didnt know about it im not pointing fingers here). the engine temperature constantly skyrocketed on your way to work (which is very bad for an engine), eventually the hot temperature caused the pump seals to fail and here we are with a leaking malfunctioning pump.

thing to do now is have the pump replaced, and make sure it is resealed properly. also check every spot you can for signs of cracks and leakage, especially with the front cover off as your replacing the pump.

make sure when you refill the coolant you use at most a 50% mix of water and antifreeze. if you live in a warm climate you can drop the mix to 30-40% antifreeze and 60-70% water. When refilling make sure you get all the air pockets out. some people have had trouble bleeding the system of air, putting the car on an upward incline helps if you cant get it bled.

good luck!

[Meantime]

Your compression is low but within "acceptable" range...

There is one thing that occurs to me here, you have a SOHC motor. The timing chain in those sometimes will wear down the front cover of the engine, causing a small hole and a subsequent coolant leak from the front cover. Since the front cover is connected to the front/top of the oil pan, it may appear the pan itself is leaking coolant, when it's actually the front cover.

You're at the mileage where the timing chain starts to do this sort of thing. Might want to take a look around (or preferably IN) the cover and see if that is the source.

[89240sx]

Thanks for the suggestions they are very good and I will update everyone once I find out what the problem is.

If anyone else has something to add pls do so =)

Thanks!

[nomuken]

another possible reason for overheating is a bad headgasket (expensive to replace)

[U12 2NR]

Sounds to me like it's your water pump is bad. You can tell if your water pump is bad by just looking at it and even loosening the belt and check the pulley for excessive movement. The water pump has a hole on it which it pours coolant out of when it's gone sour. The coolant you see at the bottom probably came out of this hole and ran down there to where you saw it.

Start your car up and run it until it's a little more than normal warm, then look at the water pump hole, if it's the problem you'll see coolant comming out.

[89240sx]

I have done that already and there was no water coming out of the water pump weep hole that is located on the top of the water pump.. If there is another weep hole on the bottom of the water pump then I will have to check that also.. The leak seems to be pretty slow.

Quote » another possible reason for overheating is a bad headgasket (expensive to replace) [/quote]

It wouldnt be that expensive for me because I have done heads before and would do all the work myself if that were the case ... the only expensive part would be sending it to the machine shop for the day ($250)

I Don't believe it is the head gasket...there is no water in the oil and my compression isnt that bad ... but I have been surprised with cars before... I'm going to replace the water pump this weekend and check the timing chain and timing chain cover

would you guys suggest replacing the timing chain (141k on motor) even if It is not rattling?

I'll keep you posted as to what it ends up being... Thanks for the suggestions... keep them coming!

TIA

Mark

[s86d]

did that fix the problem or are you back at the drawing boards. I only ask because my problems are similar (overheating) but i have the DE. Any knowledge is better than none.