Overheating!

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vsthis

Member
Joined
May 26, 2005
Messages
952
Location
Hawthorn, Melbourne
So I was driving to work a couple of days ago and i noticed my factory dash temp guage was showing about 5mm higher than where it usually sits but i wrote it off as being stuck in traffic and didn't think much more about it. That was untill yesterday morning. I was driving home from work, it's about 8 degrees out side and i was in moderate city traffic, and my temp guage started slowly climbing. It kept going untill it sat about 5-6mm below the hot line and then it droped back down to just above normal and then it started rising again. I wasn't far from home so i kept going and it dropped again.

Once i got home i popped the bonnet and started having a look.
There was bugger all pressure in the top radiator hose, the overflow bottle was 3/4 full with a whole lot of grainy residue, and the water in the radiator was down by about 800mls. Also, the water wasn't it's usual nice green coolant color but rusty and crap. When i run the engine with the rad cap off and the heater going, the water doesn't bubble out at all. It did manage to build up some pressure in the rad top hose this time though. There doesn't seem to be any milky residue in the oil either.

I've got a couple of ideas what it may be.

? dodgy water pump
? Ruptured bank in the radiator
? Dodgy thermostat
? Head gasket
? Radiator cap

It could be any of these or a few of them. Anyone got any ideas or tests i can do to isolate the problem?
 
Yeah it does seen like a water pump problem cause of the lack of pressure.
Is the car leaking any coolent? (That you know off?)
So basicly your radiator would be ok cause of when you started moving the temp went back down, But sounds like it could do with a flush as well as your engine.
Also are your fans clicking on?
You can take it to a radiator place and they can do a test that will trace any carbon, just to rule out a head gasket. Are you running the OEM gasket? Also another good thing you can do your self is do a compression check at WOT.
Good luck with it mate. :)
 
I don't think i'm leaking any coolant. Not anywhere obvious anyway.
The fans are both working and i'm running a standard OEM gasket i think.

I'll take it to a radiator place next week some time for a good flush and see if they can do that carbon test. Should all radiator places be able to do this test?

Is the water pump an easy job to change?
 
You have a 4G63 right?

I am not entirely sure if its the same as the 4G93, I know the EVO has a seperate belt for the water pump (4G93 runs off cambelt) but I am not sure if all the bolts to remove it are accessable without the removal of the cambelt and associated tensioners.

Whats involved in that?

Take the wheel off, inner guard liner, PS, AC and Alt belts,
Engine mount, maybe PS pump, cambelt covers
Check the timing marks, put everything at TDC (Top Dead Centre)
Put bolts in to retain cam position, unsure of the method for doing this with balance shafts but I am sure they will have a TDC mark on them
Remove belts
Remove water pump
Clean up water pump gasket area
Install new waterpump, being careful that the silocone sealant doesn't block anything it shouldnt.

Put everything back together :D

Flush the engine/radiator out, reprime the system (heater on full) and partially undo screw on top of thermostat housing to release air from system. Coolant will come out this hole when its done.

Simple as that really :wink: not quite, getting the timing right will be a mission if you have never done it before, not something to be attempted by an amature unless you want a rebuild... :?

Good thing if you miss ONE tooth either way the car probably wont start, and if it does it will run really rough to start with and you will know its wrong before any damage is done.

Probably looking at around $500-$800 for this from a mechanic, its about 3-4hrs labour usually.

If you don't need to take the cambelt or tensioner off (from photos I have it looks like you do), then it will be a lot easier, just remove all the crap in the way (PS,AC,ALT belts) and then remove/replace the water pump. Make sure you scrape any old sealant off the block to ensure a good bond.

Hope this helps,

Mimmo
 
Here are the pics I was refering to.

In the top photo one of the water pump bolts is covered by the cambelt, but you could probably still get to it, but in the second picture one waterpump bolt is clearly blocked by the hydraulic tensioner arm.

534508080_5200ff710c_o.jpg


534507926_18901c803f_o.jpg


There may also be a bolt behind that pulley in the centre by the looks of the design....meaning it will be a big job!

I forgot to add in the other post, to re-use the hydraulic tensioner rather than buy a new one, very slowly in a bench vice compress the tensioner piston and then place a nail in the hole (you will see two holes, one in the piston and one in the casing).

Mimmo
 
Thanks mimmo. I'm guessing it needs to be done with the motor out. Thanks for the pics and info. With any luck a good cooling system flush and a new thermostat and rad cap i might clear it up.

If it's the head gasket or water pump it might be a good excuse for a forged rebuild!
 
vsthis said:
Is there anything else i should get done at the same time? I think i would get the timing belt changed. anything else?

Yep would be a good idea if it hasn't been done (Or is around 80-100klm)to cut down on labour cost's, and what ever is involved in the 100,000klm service. (Cant think of atm, do a search I'm sure you'll find plenty on the topic)
 
I would get all the belts done, including balance shaft belts, AC/PS belts.

Also make sure you get new tensioner bearings, becuase otherwise in a few 1000km you probably have one start to squeel (out of bad luck) and then need another cambelt service to replace it.

Perhaps get them to check the condition of the front main seal (behind main pulley) and the cam seals as either of them could be starting to leak or could start to leak, and at like $20-$30 for the seals its worth it.

Yeah its done with the engine in the car, not that hard to do. Try doing it on a Chrysler Neon or Voyager!! I helped do a cambelt service one day that took a WHOLE day. Rang Chrysler to check on what sort of money they charge to do a cambelt (once we had finished) only to find out they remove the engine to do cambelts!! We did it with the engine in the car :(

Another great car is the Holden Barina, Power Steering I think needs to be disconected in order to get clearance to get the belt off.

GSR is easy to do in comparison :D

Mimmo
 
Are you sure there is no coolant leaking anywhere?

The reason I ask is after all these posts I just re-read your first post and those symptoms indicate more of a head gasket issue than a water pump one.

The only way a water pump can fail is if the housing corrodes through and starts to leak, or the blades become damaged or something (unlikely). Its not really mechanical at all, the pulley just connects to a shaft that connects to the blades...thats it, nothing to really break. If it was broken it should really be leaking coolant somewhere.

The overflow bottle issue says to me a massive increase in cooling system pressure which was perhaps brought about by a rupture in the headgasket and engine compression caused pressurisation of the cooling system...causing the overflow.

Sure there is no milky residue in the oil but all the crud in the coolant says air pressure has dislodged stuff from the cooling journals in the block.

Is there anything strange coming from the exhaust? like wet soot on the driveway when you start the car, or it spitting soot out the exhaust?

Either way if you need a head gasket, then do the cambelts and stuff at the same time as it involves the removal of the belts.

Sorry if this is causing you grief :(

Mimmo
 
Thanks heaps for all the help mimmo. I'd rather know what may be ahead of me so i can plan it a bit. I'm going to take it for a rad flush and then i'll take it down to jeff at techsport to have a look. I'd like to take it to him as it is, but it's a bit of a hike from brunswick, and i'm not keen on letting it get too hot.
 
Not sure if this was sorted out, but did you replace the thermostat yet? I had exactly the same problem (right down to the lack of pressure in the upper radiator hose) in my car, and that was the problem - thermostat sticking shut.

Considering it's 10 minutes work to replace it, and costs about $15, I'd do that before going crazy.
 
It hasn't been to jeff yet. Turns out the problem was a combination of a few things. The Radiator had a blockage of 30% and had a tiny leak in the core. The thermostat was sticking shut and the Radiator cap was not letting water from the overflow bottle re-enter the rad when it cooled down.

So, The problem was fixed with a new allow radiator, slim line fan, new thermostat, an a new rad cap. I also changed the rad hoses to some funky looking blue sillicon hoses with new clamps.

I'll post some pics in the next few days in the members ride section.

Thanks for everyones help.
 
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