<mojo>

Hi all,

I have a 2003 Lancer OZ, automatic that I have owned now for 10yrs and 150,000 miles. I need some help because the car is overheating and I am having trouble diagnosing. I will try to give all information in this post, so apologies for the length. Also, I am new to the forum, and I know a little about cars (mostly this one )

Current Symptoms:
> The car overheated on a short trip, when i noticed it going up I pulled over and turned the engine off to let it cool down.
> Opened the hood and coolant had sprayed all over the engine from the reservoir tank, and the coolant in the tank seemed to be boiling.
> Towed the car home and changed thermostat and radiator cap. Started the car and let it idle for over 1/2 hour and it did not overheat.
> Previously, the car use to overheat in idle (drive thrus, red lights, etc) but i could cool it down by turning the heat on full blast, or it would cool down when driving.
> I figured this was a fan issue, but when I changed the thermostat and watched the car run in idle for 1/2 hour, both fans would come on and didnt overheat.
> Next day, I took the car on another short trip and it overheated again (no coolant spray though)
> So the car has switched from overheating only in idle to overheating only while driving.
> One odd thing is that even though I lost coolant that sprayed and lost some coolant when changing thermostat, the reservoir tank is still full.


What would make the car overheat while driving only?

Why is the coolant level in reservoir not lowering even after i know i lost significant coolant?

I hope it is not a blown head gasket

Thanks,
Mike

<mojo>

Update - got the car home last night. Had to stop a could times. This time I noticed some knocking when the car was close to overheating. Coolant reservoir tank is still full...

2006_RA

iTrader: (1)

The coolant in the reservoir tank is drawn back in as the engine cools down.
This will not happen if the engine does not cool down or if there is a leak in the system, allowing air to enter and coolant to leave.

Confirm that the coolant level in the radiator is dropping after the car overheats please.

meckert

iTrader: (11)

You started out correctly, but with the continual driving and overheating you are more then a little likley going to need a head gasket-- that was prob the issue to begin aside from the thermostat that got stuck after 150k.

<mojo>

Thanks for the replies!

The coolant level in the reservior tank doesn't raise or lower whether the engine is hot or cold. The car sat for 3 days and the reservior tank was still 3/4 full and I know I lost significant coolant after it sprayed all over the engine.

I currently don't have milky / mixed oil, but the oil is low. I think the low oil with the hot engine maybe thinned it out and caused knocking?

Would the head gasket have pushed the coolant into and up out of the reservior tank?

Thanks,
Mike

03lances

iTrader: (14)

Most definately if the head gasket is blown it can cause this. The head gasket can blow in different areas causing different problems. In your case I would imagine you would have some white smoke coming from your tailpipe along with the exhaust having a hint of sweet smell. You could let the car sit overnight, then pull off the rad cap, start the car and while it is idling watch the coolant, it should stay pretty calm for the most part, if you see bubbles coming up through the coolant (you of course want to be sure you fill the radiator up to full before doing this so you can see the coolant, and dont run it for more than a few minutes without the cap on) then that is a good indication your hg has blown between a combustion chamber and coolant passage,

<mojo>

Thanks for your help!

I have had white smoke from the engine (the time it overheated and sprayed coolant all over) other than that, I haven't had any white smoke.

I cannot see any coolant in the radiator itself warm or cold. Also, the coolant level in the reservoir tank never lowers or raises. It stays way above the full level at all times (even after losing all the fluid when it sprayed). It seems that the radiator is not drawing any coolant in.

The car starts and runs great and will idle for over 1/2 hour without any problems, but can't handle a 10 minute drive.

Thanks,
Mike

03lances

iTrader: (14)

Let me see if I understand you, if you pull off the cap to the radiator you cannot see any coolant correct? If you can pull your rad cap and not see coolant then that right there will cause an over heat issue lol. As far as I know our car only really has as overflow tank its not really a reservoir as there is no lower hose on the tank to draw it back into the radiator.

I suggest you pull out the overflow tank and dump it back in the radiator and add anymore coolant as needed then report back after driving it around for awhile to let us know if there is any change.

<mojo>

Thank you so much for your help!

You know, I was wondering to myself the whole time how the coolant get drawn back in when the engine cools because I only knew of the top hose that is overflow from the radiator.

Bear with me for a couple more questions. I understand the radiator has to have coolant. Maybe the thermostat stuck, caused coolant to be pushed into the overflow tank and I am sitting here wondering why the radiator wont take it back it when it can't even do that.

Why does the overflow tank have fill marks if it is strictly overflow only? Seems you would never add coolant to an overflow only tank right?

If I need to add directly to the radiator, is there a way I should do it to prevent air from getting in?

Should I just discard all the coolant in the overflow and start over adding to the radiator?

Thanks,
Mike

03lances

iTrader: (14)

Answers above

<mojo>

Thanks for all of your help!

I finally got a chance to look at the car again. I tried adding some coolant to the radiator and it rolled onto the floor. A little wierd because it was rolling off the top of the radiator, but it was dark, so I will try again today or tomorrow and see if I can see where the radiator is leaking. So for now, I am thinking replace the radiator and hoping I don't find out later there is a head gasket problem too.

Thanks,
Mike

<mojo>

Thanks for your help so far! Special shout out to 03lances for answers and patience.

I replaced the radiator yesterday and the car is behaving itself right now. I drove it for over 1 hour yesterday and 1/2 hour into work this morning, and it didn't get over 1/2 hot. Please entertain the below questions so I know how to proceed.

Is it feasible that it was only a thermostat / radiator problem from the beginning that caused the coolant to be pushed into the overflow tank and spray over the engine?

In your experience, do you think something else caused the radiator to go or was 10yr 150,000 miles typical?

I have no white smoke, no sweet smelling exhaust, no bubbles in the coolant and no overheating now. Do I still need to worry about Head Gasket?

I know I am on borrowed time with water pump and timing belt, so I plan to change them. Should I attempt this myself? If I take it somewhere, how much should it cost?

Thanks,
Mike

03lances

iTrader: (14)

Thermostat would cause the overflow if it was stuck closed. Radiator going bad and the car overheating would cause the thermostat to go bad in the beginning.

A radiator will not just go bad on its own it could be from any number of things. Likely either a rock or something happened to find its way into your engine bay while driving and knocked a hole in it. Or at some point someone may not have put proper coolant in (or used plain water at some point) which can cause corrosion to eat through the radiator over time.

Head gasket is probably fine if it is no longer overheating and you have no other symptoms. The timing belt and water pump are not too difficult to change however its all about your mechanical ability. A timing belt on our car must be done correctly the first time, you likely will not have a second chance as the valves would be bent and possible piston damage if not lined up correctly.

Here is another thread I posted in about changing a timing belt.
https://www.evolutionm.net/forums/la...yl-timing.html