Overheating issues

Hello,

This could be a problem with the serpentine belt tensioner allowing the serpentine belt to slip and not adequitely spin the water pump. Another thing you might consider is making sure that there are no air pockets in the cooling system not allowing the coolant to circulate. The best way to do this is fill the system from the highest point in the system with the radiator cap off. When coolant starts to come out of the radiator cap hole, the system should be full of coolant and air pocket free. You might also consider doing a flush and fill. I know basically your whole cooling system is new, but maybe you have scale and deposits in your block, clogging the water jacket ports. The last thing I can think might be your problem would to be to double check to make sure you have the correct temp thermostat. Let us know what you find out.

Thanks,
Alex
2CarPros

Water pump is driven by the timing belt, all timing components have been replaced. Correct thermostat temperature is in, this is the second thermostat as a precaution 170 degree. Vacuum filled cooling system to eliminate air pockets. While the heads were off I cleaned all the water cooling jackets with a brush and then chemically flushed the engine after install prior to filling with coolant. All hoses are also new.

Thanks, Jerry

Run the same combustion gas test and see if it's still leaking under compression. (A cheat to test this is to put a balloon over the coolant fill, if it inflates really fast you have a leak) Have seen head gaskets leak like a one way valve before on them. Have also seen blocks crack and only leak under pressure.
Whose water pump and gaskets did you use? Some of the aftermarket parts are real junk.

Have you pressure tested the radiator cap? Have seen bad caps cause fluid to over flow and overheat. Also check the coolant temperature sensor. It could be giving a false reading.

Does the cooling fan run when the engine warms up?

Did you replace the water pump the impeller? It could be degraded not circulating the coolant correctly.

Gates Murray and felpro

I have done all of this

Engine Cooling problem
1993 Subaru Legacy 4 cyl All Wheel Drive Automatic

what test can i run to find out y my car overheats

if the temp guage goes up and you do not loose fluid then the first thing I think about is the thermastat. If you are looseing fluid then I would have the system pressure checked. A number of things can make it overheat, !. not enough coolant, 2, clogged system, 3, a bad themstat. With the thermastat is usually the problem that I would change first first

My engine keeps overheating. I have replaced the timming belt the thermostat the waterpump all the hosses and the radiator recently. It worked fine for about 3 weeks and then the temp began t rise as I drive it . When I am stopped at a light t is in the middle. I also noticced that it makes a gugelling noise when I ress on the gass pedal. I looked last night the transmission fluid was low. I want to know what I should do. My friend says there may be an air bubble in the system causing it to make the guggle. I look forward to your help

bleed the system, you may have an air pocket thats not allowing the coolant to go into the heater core, also check your engine coolant temperature sensor

I have a subaru legacy 1990 overheating, automatic, all wheel drive. I have changed the thermostat 3 times, water pump, timing belt, got timing reset, filled system and bled, blown out the heater core and put in an expensive head gasket sealer all to still overheating after 15 mins of driving. I am at a loss. The bottom radiator hose stays cool, I don't know if that's normal. Please give me an idea as this is my kids car and we need another 6 months out of it if possible. Changed all the above and still overheating I don't know what to do now. The overflow bottle fills up overflows and then sucks back in after it cools down. Also the heat will blow hot and then go cold before it starts to overheat.

Sounds like you need to get the radiator unclogged. Lower hose should warm up with the engine.

It blows cold because there is no coolant in the system to heat the air.

Any suggestions on how to do that, it's a newer radiator

There is coolant it has been filled and topped off after each overflow

It has to be done at a radiator shop.

I have replaced the thermostat twice, put in a new water pump, replaced the radiator, replaced the head gaskets twice, and it still overheats. It will over heat and the heater will be putting out cold air, then the heater will come on. The radiator will sometimes overheat and overflow into the overflow bottle, but at the same time one half of the radiator is hot and the other half is cool to the touch.

Hi DennSubaru and TY for the donation

but at the same time one half of the radiator is hot and the other half is cool to the touch. It shouldn't be-should equally be hot across the radiator. That coolant is not circulating. take the thermostat out and run it if its still doing it make sure the water pump is doing its job if it is-try bleeding it for airlock and report back

Water pump check:

One way to test for a bad water pump is to squeeze the upper radiator hose when the engine is hot and idling. Careful, because the hose will be HOT! If you do not feel much coolant circulating through the hose when you rev the engine, the pump may be bad. The other cause might be a bad thermostat that is not opening properly (remove and inspect the thermostat), or a clogged radiator.

I have a subaru legacy outback that is now overheating constantly and I think it continues to lose water. I don't drive my car on the freeway anymore. I try to keep it under 55mph and it seems to overheat less. I have no idea what it could be. I took it to a radiator mechanic and they replaced the plastic parts where the hoses are attached because those pieces were cracked. I also put a new radiator hose on because that blew. Excessive pressure still builds up in the hose and you can actually hear the water boiling. The mechanic didn't think it was the thermostat because when the radiator is filled, the car doesn't overheat. What would cause the car to lose water? The radiator doesn't leak and the inside of the radiator is clean. I get it flushed at least once every two years. I just drove to work this morning and the fluid was just pouring out of the overflow by the time I actually made it to the office.

Try replacing the thermostat-and check if the water pump is doing its and fan coming On on time if okay try bleeding the cooling system-don't work get it block and pressure tested-

Engine overheats almost immediately after starting. Radiator is full. Was told it might be a blown head gasket. How do I diagnose the problem?

Thank you

If you see bubbling in the coolant reservoir when the engine is cold, suspect the head gasket. Also, there won't be any steam and the coolant and hoses will still be cold.

Your mechanic will use a special tool to check for combustion gases leaking from the cylinders into the cooling system. It is a glass cylinder with two chambers partially filled with a dark blue liquid. Air is drawn through the fluid from the radiator. If combustion gases are present, the fluid will turn bright yellow. That will be conclusive of a leaking head gasket.

caradiodoc

i have a 1995 subaru legacy with a overheating issue, radiator was flushed and burped and still overheats after 10 mins of driving it makes no sense. mechanics are not sure whats going on or never worked on a subaru before, coolant has no bubbles so i doubt its headgasket,,,maybe thermostat..water pump but im hoping its a easy fix. Please help.

dont rule out a head gasket. from the overheating that may be the issue

i would change the thermostat first to see but get a leak down test to confirm no head gasket

Roy

im having a issue getting the two bolts off of the thermostat housing someone has stripped them and they are rusty so all attempts to take it off have been unsuccessful im not sure how im going to get these bolts off. is a leak down test usually free?

no, runs about 80-100 bucks

roy

are the cooling fans working? also, turn the heat on... does it blow hot? if not, check the heater hoses going to firewall.... if they are both cold, its likely your engine is airbound, and not allowing coolant to flow to your heatercore...

Sometimes the car overheats after driving 3-4 miles, other times after driving 12-15 miles it doesn't overheat at all. Once when it was hot, I took the bleeder plug out and steam was shooting 2 feet in the air, at the same time you could stick your finger in the coolant in the opposite side of the radiator. The dealer said the headgaskets were blown, the car ran w/o any misses/hesitation at low or high speed. Wouldn't bad headgaskets affect performance? Could the overheating be caused by something else? (something less expensive to repair $1,900)
Thanks, Dan

You best get a cooling system test done to prove a faulty head gasket, this can be done with a simple chemical test of the gasses in the radiator. this will be conclusive. do this first.

Mark (mhpautos)

I would suggest that the thermostat is sticking shut sometimes. Aftermarket thermostats are mostly made in China and have spotty quality control, best to get the OEM replacement from a dealer (no, I don't work for a dealer or know anyone who does).

Engine Cooling problem
1991 Subaru Legacy 4 cyl Front Wheel Drive Automatic

We have replaced the tstat timing belt waterpump and have flushed the system several times. But it still keeps overheating and pushing the water out of the overflow tank and this morning after sitting all night the system was still pressurized what can be causing this and can I fix this problem

the radiator can still be severly clogged. also try changing the radiator cap if you havent already, otherwise the system will need to be pressure tested to help deterimine where the clog may be,.

before addressing any of the previous post. check/change the engine coolant temp sensor, and make sure the radiator fan is coming on when it should, you will also need to hardwire the fan directly to the battery to make sure it is even any good.