Manager Forum

car came to shop with over heat problem

test drove on highway no problem with temp. installed thermostat thought maybe sticking. customer picked up car, came back, same problem. got more of story; driving 50-55 under most load, temp guage would climb to hot, they would accelerate to 60-65 temp come down, as long as rpms were over 2000 rpm. we verified complaint, stopped car when warm verified. cooling fans running on high; they was air blowing from the fans, was cool air and hose thermostat is in by water pump was cool to luke warm. removed radiator cap at that time; pressure in system nothing out of ordinary and the radiator hoses weren't rock hard and just sitting in shop stall, car has no overheat problem and only has 57000 miles on car.

any help and advise would be great.

Thinking water pump impeller.

Im with Steve on this one. Have seen more and more sheared impellers lately. Plastic impellers on steel shaft

jbadenoch wrote:Im with Steve on this one. Have seen more and more sheared impellers lately. Plastic impellers on steel shaft

That combination equals job security for us.

Ahhhhhh. I wouldn't be real quick to condemn the water pump though. I had one a few weeks back with a similar issue. Replace water pump and thermostat. Same problem. Replaced radiator and the overheating issue was gone. The extremely small ports in today's radiators creates some problems with flow if there is any amount of restriction whatsoever.

You are sooooo right. The condition described sounds like low flow. Anything that'll cause low flow could be the culprit.

Oh yes. I almost forgot about the one I had that had a collapsed lower hose. Talk about difficult! I finally decided that I was taking the hoses off and physically cutting them open. An, that is what I found.

It's called a fun job. The satisfaction of finding the problem and fixing it.

here is what we got great ideas with water pump and radiator we thinking same try one or the other however customer came in with a forum he read describing his car 2 a T and the gentle man that wrote it gave an explination and a bandaid remedy drill 2 hole in the thermostat pressure disc allowing coolant to pass to the thermostat faster 2 get it to open hence in mechanics knologe not enough presure and flow to thermostat so we did what customer wanted drilled holes test drove no over heat BANDAID working 4 now

The only time that drilling the t-stat has helped me were times that I had a ever so slight combustion leak into the cooling system causing an air pocket by the t-stat which insulated it from the coolant....

I would do the same thing on a lot of 4 cylinder Chrystler products because of head gasket issues causing a gas pocket like liljoe mentioned. Eventually it would overheat in a catastrophic way, this was all done with the customers knowledge as a temp repair.

I still fall back to an old trick i used when installing t stats. If there is no air bleeder or it's frozen i use a Tylenol pill and stick it between the t stat plate holding it slightly open. It allows the system to bleed and a fill and cap usually works. After a while the pill dissolves and all is well. I remember certain G.M. vehicles that needed the front end jacked up, drivers door open, rpm's at 4k, prayer candles and a witch dr with a hand full of chicken bones to get the coolant circulating to get heat.

I use a vac tool now. It sucks a vac into the cooling system then you drop a hose into a pale of coolant, open a valve and let it suck it into the cooling system. Works great.

Dang Kiser that shook loose some cobwebs. I worked with a fella years ago that put an aspirin in every stat. I was prolly 13-14 then and had completely forgotten about it and him. Some good memories of the old dude..thanks man!

have to say then i never thought of that great idea