Overheating problem! Please help!

[EZcheese15]

I have an '81 210 that I am having an overheating problem with. I've replaced the thermostat AND the waterpump, but the problem is not cured.

I have also run the car on the interstate at about 70 mph for a couple miles, and the problem was even worse, so it's not an airflow problem to the radiator. The fan clutch also seems to be working properly (I think).

What else could cause this problem? My only other guess is that the radiator is clogged internally or something. But I want a second or even third opinion as to what it could be before I go buying a new radiator.

Any help is appreiciated.

Thanks!

[eastcoastchaos]

you probably just have some air trapped in there. run it with the radiator cap off and look for any bubbles. once the bubbles stop your problem should be fixed.it worked for me

[EZcheese15]

you probably just have some air trapped in there. run it with the radiator cap off and look for any bubbles. once the bubbles stop your problem should be fixed.it worked for me

Thanks for the suggestion, but believe me, that's not the problem.

The coolant has been changed probably 5+ times and the problem still exists. I have bled out all the air every time.

One thing strange though, when you fill the car up with coolant and let it run until the thermostat opens...you can feel the upper radiator hose get hot after the thermostat opens, but if you look into the radiator, there seems to be no flow. The coolant stays stagnent. Which makes you think the waterpump isn't working, but I just changed that and it has the same problem. Also, the old waterpump appears to be in good condition anyway.

[Eikon]

that really sounds like a clogged radiator.

Here's a good way to check if your water pump is working...

Let the car warm up to normal temps... Turn on your incabin heat. As high as possible with the highest blower setting. Put it on the dash so you can feel the temp with your hand.

Do you get a good flow of heat that remains hot and constant for a few minutes? If your water pump isn't moving any fluid, it wouldn't be able to move any coolant through the heater core. So, you would get a decent blast of warm air at first, but as the coolant (that is not moving well or not being forced through the heater core) cools down, you would feel your heated air stop feeling hot.

If you get constant hot air though your heater, your water pump is moving coolant through the system and it's fine.

If you get a little hot air, then it cools to luke warm.. then you have a bad water pump because it's not circulating coolant through the system.... (or I suppose you could have a clogged heater core as well).

Check it out for us and report back..

I would guess that if you have good constant heat, that your water pump is fine, and you have a clogged up radiator.

[EZcheese15]

Eikon, thanks for the reply!

You have some very helpful tips. I am leaning towards thinking the radiator is clogged. I can run my heater and it blows hot the entire time. That, and like I said, I already replaced both the thermostat and the waterpump, so I'm ruleing those out of the equation.

I suppose I'll pull the radiator, see if I can't see a problem with it. If I don't see anything, I think I'll take it to a radiator shop and have them rod it out.

When I finally figure it out, I'll be sure to post back

[Eikon]

no prob...

touching back on the radaitor issue..

you mentioned the upper hose being hot.. How about the lower?

Obviously if the lower hose is not hot, then coolant is not flowing out of the radiator, and that is your issue.

if the lower hose is hot, you might be getting some flow. Perhaps not enough to keep the engine cool.

If it's not the radiator.. then it's time to start investigating your head gasket as that can also be a cause for overheat. Although their are usually other signs.

Good luck with the radiator!

BTW.. how's that Spec V treating you?I had a black 02 and loved it. I drove it for about 15k miles and sold it to get rid of the payments. Then I bought an S14.. drove it for about a year and sold it at a profit. Then I bought my S13 'vert and have let it drive me to bankruptcy (almost).

[EZcheese15]

I haven't checked the lower hose. I'll do that tonight.

As far as the headgasket goes, I KNOW that's not it. I didn't mention, but I just rebuilt this engine earlier this year and have practically no mileage on it (probably less than 50 miles on rebuilt motor).

And headgasket has been replaced 3 times already since the rebuild because I've had to take off the head for various reasons (leaking freeze plug that the machine shop put in). Anyway, there is absolutly no way it can be the headgasket, I garuntee it

[navysnail]

just as a check, if you have the radiator out put some water through it, it should flow through fairly fast. also check your pressure cap, it should have the pressure on the top, a shop can check that real quick.

[NISTECH]

+1 for radiator issue. Upper lower hose check, definitly. lower cold means minimal flow.