Cooling Problem...Help?

[ZohanIsBack]

Car keeps overheating on warm days (60+ degrees). It has the three speed auto so naturally it runs at 3600rpms going 70mph. It won't heat up if I stay at 55mph, but as soon as I speed up, it will over heat to 240-260 degrees. So:

I suspected a stuck t-stat. Checked, t-stat was removed by previous owner.

So what now? New water pump? The car has 80k original miles on the engine, so I am guessing it could be getting old and gunked up. Any other ideas?

Oh yes, and should I reinstall the new t-stat I got, or leave it deleted?

Edited April 22, 2011 by ZohanIsBack

[5thhorsemann]

you need the stat for propeer temp management, reinstall. Flush the cooling system.

[ZohanIsBack]

Great. Thanks!

[az240z]

I would send the radiator out to be cleaned.

[AZ-240z]

If you are getting that much of a temp extreme, I would pull the radiator and have it rodded out, boiled, pressure tested, and definitely install the correct thermostat. Restricted flow in the radiiator core will definitely defeat the purpose of the cooling system. before taking it out, though, being very conservative, I would also put a chemical flush through the whole system to make sure there is not a large sediment buildup in the block which may not allow efficient heat transfer to the cooling medium. Not that expensive to do if removing and installing components yourself.

Dan

[ZohanIsBack]

It's doesn't look too bad through the top--that's not saying a whole lot though. I'll run some firestone radiator flush through it first.

[FastWoman]

Another vote for pulling the radiator and dropping it at a shop for rodding out and cleaning. Also put in a 180 thermostat. That's not your problem, but you need one. Finally, it's unlikely a bad water pump would be your problem. The vanes would have had to rust away, which would be unlikely.

Prestone radiator flush does little or nothing to help a corroded radiator.

[ZohanIsBack]

Well, I already had a bottle of the super strength stuff for neglected radiators so I figure it's worth a shot to see how it works. As far as taking it into the shop goes, does anyone know how much that runs? It's $80 for a new one, so.....there's a lot at stake here. I do appreciate all your input though! I did get a 180 t-stat.

[5thhorsemann]

Flush the system BEFORE doing anything with the radiator. If there is a buttload of slop in the block the flush may clog parts of the new/ referbed core. Just my opinion.

[ZohanIsBack]

Agreed, well....I'm putting in the new t-stat today, so we'll see if it works. Had to tap new bolt holes though....The stupid previous owners stripped the threads and glued the bolts for the t-stat upper unit in place. Idiots...

[tlorber]

Are you saying that its $80.00 for a new radiator? That sounds very cheap. MSA sells them for around $275.00 and I recently bought a 3 row (the same one they sell) for around $225.00. You might check to see how many rows yours has.

[ZohanIsBack]

It was, but yeah, I have no idea as far as quality is concerned.