13 replies to this topic

[samsungd838]

I bought a Liberty with overheating problem recently.

 

I picked up the car at night,when i drove it home, i realise that the heater is not working. But it takes me home without overheating, its about 8 kms continous driving without much stop unless on the traffic lights. 

When i get home, i let the car idled for about 10 minutes,no signs of overheating. Continues to idle with air con on, still runs like normal, so i turned the car off.

 

On second day is about 30 degrees, i drove it to my friends place to pick him up, it starts to overheats on the way back.

I turned heater on,now the heater is HOT, the temperature drops to normal very quickly. But it starts to climbs up again when i comes to the last traffic lights before i get home. The temperature drops down as soon as i start to rev up the engine.

When i get home,the temperature was shooting to the top as soon as i parked the car., i pop the hood up straight away and quickly checked engine. Engine is pretty hot but no bubbling in the overflow bottle. So i assume its not a head gasket problem.

The bottom hose is hot and both fan is on. I turned the car off and let it sit for about 5 minutes and started it again, it started normal without any issue, and the temperature has dropped back to the middle of the gauge. Let it idle, no problem, turned on air conditioner for about 2 minutes, temperature going up again, but it still dropped back when i rev up. Turned off the engine and let it cool down.

 

I drove the car on the ramp. i checked thermostat, the thermostat in the car has been cut and let the coolant flow freely in the engine.

This tells me previous owner had already tried something to trouble shooting the problems.

Installed new thermostat and took it for a drive, it takes a while for the car to heats up, but once it heats up, it will overheats very quickly. Checked engine while idling, the top hose(from engine to radiator) heat up quickly, but the lower hose wont heat up until the top hose gets very hot. 

 

Replaced timing belt,idlers and the water pump, the old water pump was a bit rusted and has a bit gunk inside.

But the car still have same issue, started check on heater core since the heater its not working properly.

Found out the heater core might be blocked.

 

As followed by insttruction video from youtube, undone both hoses connected to heater core, and flushed it by hook up garden hose to the outlet hose. It was clogged, muddy water came out of inlet hose at first flush, once the water runs through a bit better, i blowed it by air gun, flushed by garden hose again, now water can run throught it nice and freely.

 

Hook up the heater core hose back, fill up and radiator and let it idle. But the heater still seems not working properly. Took it for a drive, the engine is warming up gradually but still overheats after a distance. But the cooling system seems working better, i drove it home and let it idle, it cooled down, turned on the air conditioner to maximum and sit in the car for about 20 minutes, the temperature still normal.

 

Now the car seems like only overheats while i am driving and came to a stop at red light. Once rev it up the temperature goes down.

 

I drained radiator a little bit, and filled up overflow bottom with water, checked it after the engine warmed up. The water in the overflow bottle hasn't been pushed out or sucked in.

 

 

I know if the HG is blown, the water/oil would be found in wrong place or the water in overflow will smells like exhaust, it doesn't happen in my car. I have also swapped radiator cap/ thermostat from my 98 outback, because they both have SOHC EJ25 engine. The problem remains.

 

Could there be a leak in my cooling system so the coolant not flowing properly to cause the overheating problem? If so, how can i find it out? Should the top hose feels pumped(solid) while the engine is warmed up if there is no leaks in cooling system?

 

Also i found a receipt in the car, it stated a compression test had been done by local garage by no leak has been found, they also have no idea why the car is overheating. So this means the HG not blown as well ?

 

Thanks for the patient of reading this thread, any suggesting would be great.

[Jimbo]

Quite possible the coolant temp sensor may be playing up. Its located in the water crossover pipe under the intake manifold. Sometimes a blown HG wont show up on tests, i went through the same with my old Legacy GT-B. All test showed negative to a HG leak but it ended up being that anyway. Perhaps start with the sensor first as it's relatively easy to do,

[samsungd838]

Quite possible the coolant temp sensor may be playing up. Its located in the water crossover pipe under the intake manifold. Sometimes a blown HG wont show up on tests, i went through the same with my old Legacy GT-B. All test showed negative to a HG leak but it ended up being that anyway. Perhaps start with the sensor first as it's relatively easy to do,

Hi Jimbo, thanks for the quick reply.

I am going to have a look the coolant temp sensor tomorrow. 

Did you have to pull the head off to see if the HG really blown?

I have heard people saying that the HG won't start to leak until the engine is hot, thats why all the test shoed negative result.

[Jimbo]

Well, in my case, we hadn't tightened the heads properly when we refit them to another motor. Still didn't show any signs of a leaking head gasket, only symptoms (over heating etc). Eventually i said fork it and pulled out the engine to have the heads reco'd and new gaskets put in. As i said, the HG's were gone but didnt show any positive results to any tests.

As the Boss just said, a blocked radiator may also be an issue. May well be both hoses are hot but may not mean sufficient flow. Although in saying that, if it wasn't flowing properly due to a blockage, it would find it's way out someway else and you would soon know about it.

Whip out your radiator, give it a good hosin' and try swapping out the temp sensor for another.

If they fail to quell your problem, im afraid the diagnosis wont be very good.

[samsungd838]

What year lib? Manual or Auto?

Radiator possibly blocked too?

Hi, its a 1999 Model with Manual transmission.

I have connected garden hose to radiator but water just flowing freely.

[samsungd838]

Well, in my case, we hadn't tightened the heads properly when we refit them to another motor. Still didn't show any signs of a leaking head gasket, only symptoms (over heating etc). Eventually i said fork it and pulled out the engine to have the heads reco'd and new gaskets put in. As i said, the HG's were gone but didnt show any positive results to any tests.

As the Boss just said, a blocked radiator may also be an issue. May well be both hoses are hot but may not mean sufficient flow. Although in saying that, if it wasn't flowing properly due to a blockage, it would find it's way out someway else and you would soon know about it.

Whip out your radiator, give it a good hosin' and try swapping out the temp sensor for another.

If they fail to quell your problem, im afraid the diagnosis wont be very good.

Well i hope its the temperature sensor. 

So does this engine only have one temperature sensor which is connecting to both ECU and temp gauge?

If its ending up to be the HG, do you recommend to pull the motor out to replace the HG, as its to hard to do it when the motor in the car.

I can borrow a engine hoist off my friend. I am be able to just sit this boxer engine on a rim to work on? Because i dont have a engine stand.

[Jimbo]

You can't do a HG with it in the car, not a chance. If you can get it out and sit on a rim it should be okay provided you have enough room to work. I would just pull the engine out, buy a kit and give it to mechanic, save heaps on labour. Thats if you cant be bothered DIY. If you have the time, resources and space, go for it.

[Scuba-Roo]

You can't do a HG with it in the car, not a chance. If you can get it out and sit on a rim it should be okay provided you have enough room to work. I would just pull the engine out, buy a kit and give it to mechanic, save heaps on labour. Thats if you cant be bothered DIY. If you have the time, resources and space, go for it.

Ive seen it done before in the engine bay.

Once you got the engine out its pretty easy to finish it off. Just follow the step by step instructions in the service/repair manual

[JDWhiteWRX]

It can be done with motor in but you would be crazy to do that, my back hurts just thinking about it. Make sure you get the heads machined, new gaskets, new rocker cover gaskets and not a bad idea to get new bolts.

[allpaw4]

Get new head bolts. You could get away with it, but if you have the motor out, you might as well do the job properly.

[RX25SE]

Before you go ripping the engine apart, try a new radiator(or have yours cleaned by a radiator specialist) as this may be the cause of a blown head gasket. Just because it was flushed in the driveway and water flows freely does not mean it can cool an engine.
If you do have a head gasket issue, then fitting a new radiator along with the gaskets is a wise move.

[MrSober88]

Have you made sure to have got 100% of the air out of the system?