K Engine Head Warp On Cold Winters Nights

[bruce]

Got this heating issue when I drive my 5k corolla on a cold winter Hobart night.

 

When I first drive the corolla, starting with a cold engine, until it warms up 5-10 minutes later, the temperature gauge goes up to 1/3, then the thermostat opens up and lets cold coolant into the engine. The temperature rapidly goes down. Then the engine starts to run rough and I have to keep the revs up so it won't stall at the traffic lights. It last around 20 seconds. I suspect the sudden flow of cold coolant from the radiator warps the head on the block and starts to let coolant to seep through the head gasket. When I check underneath the oil cap after this event, there is a creamy looking substance; likely indicating that coolant/water is entering into the engine oil.

The thermostat and water pump is a couple years old. It only happens in winter time.

 

Not a major problem, but just curious if anyone has encountered this before, and if its just a matter of planing the head and putting on a fresh head gasket on?

Or if its a K-engine head design characteristic with hot spots? Perhaps the air-bleed valve in the thermostat needs to be opened up more?

[Old fella]

Got this heating issue when I drive my 5k corolla on a cold winter Hobart night.

 

When I first drive the corolla, starting with a cold engine, until it warms up 5-10 minutes later, the temperature gauge goes up to 1/3, then the thermostat opens up and lets cold coolant into the engine. The temperature rapidly goes down. Then the engine starts to run rough and I have to keep the revs up so it won't stall at the traffic lights. It last around 20 seconds. I suspect the sudden flow of cold coolant from the radiator warps the head on the block and starts to let coolant to seep through the head gasket. When I check underneath the oil cap after this event, there is a creamy looking substance; likely indicating that coolant/water is entering into the engine oil.

The thermostat and water pump is a couple years old. It only happens in winter time.

 

Not a major problem, but just curious if anyone has encountered this before, and if its just a matter of planing the head and putting on a fresh head gasket on?

Or if its a K-engine head design characteristic with hot spots? Perhaps the air-bleed valve in the thermostat needs to be opened up more?

Mate thats a strange one. One would normally associate creamy oil under the 710 cap with a blown headgasket/crackedhead. Have a look inside the top of the radiator with theengine running to see if there are bubbles forming. If so then it is probably one of those. Also try parking the car nose up on a steep driveway/hill and see what level the coolant is inside the radiator. A slight possibility is an air lock inside the head.

It probably wouldn`t hurt to re-tension the head either, if you can get hold of a torque wrench.

If it does turn ouy to be a head problem, please don`t try to fix it with a chemical additive to the radiator. That is only a stop gap and will lead to bigger problems down the track.

Anyway, goodluck.

[Falken_KE30]

I got same problem, except mine don't run crap like you explain. but i still get a smidge of the creamy stuff under the cap. I think thats mainly from condensation. i mean we are in tassy in winter :bash:

 

but yeah, try flushing the cooling system, then turn heater on to hot and refill the system, let it run for a few minutes with out radiator cap and then top up if needed.

 

Cheers

Dan

[Felix]

Maybe look at fitting a hotter thermostat. Make sure you use one with an air-bleed hole.

 

Do you do a lot of short trips? If so the gunge under the radiator cap could simply be from condensation as Dan mentioned in the above post.

Edited June 22, 2009 by Felix

[altezzaclub]

The temperature rapidly goes down

 

That's not meant to happen. Thermostats open & close a little bit at a time, so they keep a temperature steady.

 

You could pop the 'stat out and heat it up in a pan of water with a thermometer to check it opens at the temperature stamped on it, and that is does open all the way and close nicely, but I feel the problem lies elsewhere.

 

Have the car level and fill the radiator up to the very top, as mentioned above, then start it w/o a rad cap and let it warm up. If the gasket is leaking water into the oil it usually leaks compression into the water and the top inch of water gets pushed out over the floor while you watch.

 

Once the thermostat opens then the bubbles clear and it runs OK. Also, if the head gasket is leaking it is very hard to start (and often on three cylinders) first thing in the morning, from the condensation on the plugs. After that its fine all day.

 

Let us know how you go-

[rob83ke70]

If it is pressurizing the coolant system, the highest combustion chamber pressure is found when the engine is cranking (not started), maybe disconnect the trigger wire for the coil to disable spark and take radiator cap off, and observe coolant with engine cranking, if it bubbles, then it is pressurising the cooling system with combustion gasses.

 

interesting experiment actually on a side note, compare compression readings with a compression gauge (the sort that is screwed into the spark plug hole) with the engine cranking and with the engine idling (obviously with the lead that you are not using grounded via a test spark plug or similar) and note the pressures...

 

Robert.

[Felix]

the highest combustion chamber pressure is found when the engine is cranking (not started)

 

You think?

 

The ignition of the compressed fuel/air drives the piston downwards. The peak cylinder pressures with the engine running at what are more likely to be 4-5 times the cranking pressure.

 

the cylinder pressure developed when an engine is running will be higher than that shown in a compression test for several reasons.

 

* The much higher velocity of a piston when an engine is running versus cranking allows less time for pressure to bleed past the piston rings into the crankcase.

 

* a running engine is coating the cylinder walls with much more oil than an engine that is being cranked at low RPM, which helps the seal.

 

* the higher temperature of the cylinder will create higher pressures when running vs. a static test, even a test performed with the engine near operating temperature.

 

* A running engine does not stop taking air & fuel into the cylinder when the piston reaches BDC; The mixture that is rushing into the cylinder during the downstroke develops momentum and continues briefly after the vacuum ceases (in the same respect that rapidly opening a door will create a draft that continues after movement of the door ceases). This is called scavenging. Intake tuning, cylinder head design, valve timing and exhaust tuning determine how effectively an engine scavenges.

Edited June 22, 2009 by Felix

[rob83ke70]

I will requalify my statement there:

 

Cranking combustion chamber pressure is greater than combustion chamber pressure at engine idle.

 

Was mid-intake of very strong coffee, not lending as much thought as I should have to what I'm saying.

[bruce]

Thanks for all the feedback.

 

Maybe look at fitting a hotter thermostat. Make sure you use one with an air-bleed hole.

 

Do you do a lot of short trips? If so the gunge under the radiator cap could simply be from condensation as Dan mentioned in the above post.

 

The thermostat I got was for a ke30/ke55 from Bursons. It did have a small air-bleed hole with a stud in it. A mate who was a mechanic said to cut the stud out to free the trapped air better, but I left it in there (thought it had to have a purpose). Probably could cut it out and make the hole a bit bigger.

I do make the occasional short trips around town, but no cream forms under the oil cap, unless the weather is real cold and then the engine runs rough.

 

 

That's not meant to happen. Thermostats open & close a little bit at a time, so they keep a temperature steady.

 

You could pop the 'stat out and heat it up in a pan of water with a thermometer to check it opens at the temperature stamped on it, and that is does open all the way and close nicely, but I feel the problem lies elsewhere.

 

Have the car level and fill the radiator up to the very top, as mentioned above, then start it w/o a rad cap and let it warm up. If the gasket is leaking water into the oil it usually leaks compression into the water and the top inch of water gets pushed out over the floor while you watch.

 

Once the thermostat opens then the bubbles clear and it runs OK. Also, if the head gasket is leaking it is very hard to start (and often on three cylinders) first thing in the morning, from the condensation on the plugs. After that its fine all day.

 

Let us know how you go-

 

Usually on a 15-20 degree day the temperature gauge gradually goes down when the thermostat opens, but it rapidly goes down during <10 degree night.

 

I did let the engine idle for ten minutes with the radiator cap off and after a while the coolant rose up and split over (no bubbles). Looks like it is leaking compression. Did not realise I had a head gasket problem.

Perhaps the sudden temperature change from the thermostat opening made it more severe.

 

Haven't drove the corolla for a few weeks (just got a family car), but I took it for a spin last weekend and the temperature gauge stays cold all the time. The thermostat might have got stuck open. Planning on rebuilding the engine soon.

[rob83ke70]

normal for the coolant to rise and flow over if running the engine without a cap, if it is leaking compression and pressurising the cooling system the result will be rather violent and catastrophic.... coolant will bubble and go everywhere very fast.

 

the stud in the air bleeder hole is so air can get through when bleeding but it doesn't leak too much coolant AROUND the thermostat when in operation, if you cut the stud out the overall temp of the car will come down a bit. I'd probably leave the stud in. K motors aren't hard to bleed anyway.

 

Robert.

[bruce]

Thats what I though. The coolant heating up and expanding; and the water pump running.

Just considering what altezzaclub said before

 

Have the car level and fill the radiator up to the very top, as mentioned above, then start it w/o a rad cap and let it warm up. If the gasket is leaking water into the oil it usually leaks compression into the water and the top inch of water gets pushed out over the floor while you watch.

[rob83ke70]

BIG BIG BUBBLES violently erupting from your radiator, spewing bubbling coolant all over everything...... that would be a head gasket....

[webb]

BIG BIG BUBBLES violently erupting from your radiator, spewing bubbling coolant all over everything...... that would be a head gasket....

 

 

I knock off work at 6am in Huonville (tas) its f@$king freezing too say the least. too make the 30km trip home on the highway I have too stop about 3 or 4 times sit on the side of the road and let it warm up.

 

But I only have this problem in the extreme cold. I have a new thermostat, dunno why it does it...

[Felix]

If the car never gets to operating temperature, boil the thermostat in a pot of water with a thermometer. Make sure it closes all the way up when cold.

 

If the thermostat checks out ok consider trying this:

 

In very cold climates try partially blocking the radiator as an experiment. Maybe get a bit of cardboard and put it in front of the radiator so it say blocks off half of the fins. If this makes an improvement make up a blind/shutter system that can be controlled from inside the car.

[Taz_Rx]

If the car never gets to operating temperature, boil the thermostat in a pot of water with a thermometer. Make sure it closes all the way up when cold.

 

If the thermostat checks out ok consider trying this:

 

In very cold climates try partially blocking the radiator as an experiment. Maybe get a bit of cardboard and put it in front of the radiator so it say blocks off half of the fins. If this makes an improvement make up a blind/shutter system that can be controlled from inside the car.

 

To words for felix's above experiment...

 

Gaffa Tape!!!! :D :bash: