Howdy all.
After a very fun 1000km trip to Kangaroo Island, my 380 has developed a heating issue.

Symptoms:
-At idle, after about a minute the temperature guage will shoot up to about 3/4 or more on the dial.
-After taking off, about ten seconds later, the guage will then go back to just under half way, the magna/380 std temperature location.

-If I keep the RPM over idle after it has heated up, the temperature will drop just as it would if I started moving
-Also, if I put in the clutch going 100km/h (down an Adelaide hill this afternoon), it will overheat just as it would if I were idle.

Thus, I have concluded that the main issue is when the RPM is at idle.

Another couple of notes:
-Water pump replaced with timing belt ~4k ago. 103k on the clock.
-I had a look under the body earlier today and there was some coolant on the drivers side frame under the body. I looked from the engine bay and it appears to be leaking onto the power steering boot. This may be innacurate as I am no mechanic.

Any help?

I am starting to lean towards it being the thermostat. If so, what do they cost for the right product and how much man hours am I looking at paying my mechanic?

Thanks in advance,
Oscar

Oscar,


Warm it up a bit then feel the top & bottom radiator hoses.
If the top hose is hot and the bottom hose is cold then it's odds on your thermostat is cactus.
Easy DIY job to replace, I did mine in about 15 minutes a couple of years ago when my thermostat croaked.
IIRC a new thermostat cost me around $35 from the stealership.
Don't drive it if it continues to overheat.


That said, your symptoms don't sound like a stuffed thermostat. If your thermostat was cactus then it would overheat at all revs and not just at idle.
If it's not your thermostat then I don't know what the problem is, and someone like Mal should advise.

Oscar,


Warm it up a bit then feel the top & bottom radiator hoses.
If the top hose is hot and the bottom hose is cold then it's odds on your thermostat is cactus.
Easy DIY job to replace, I did mine in about 15 minutes a couple of years ago when my thermostat croaked.
IIRC a new thermostat cost me around $35 from the stealership.
Don't drive it if it continues to overheat.


That said, your symptoms don't sound like a stuffed thermostat. If your thermostat was cactus then it would overheat at all revs and not just at idle.
If it's not your thermostat then I don't know what the problem is, and someone like Mal should advise.

Ah yes, another point,
The top radiator hose was hot, but the radator at the top & cap wasn't hot and was indeed cold.

I would say thermostat as higher revs will push more coolant if only partly closed

Don't use any aftermarket thermostat either, is not worth it

I would say thermostat as higher revs will push more coolant if only partly closed

Don't use any aftermarket thermostat either, is not worth it

Thanks Mal.
So, i'll get my mechanic to check that. Thanks for the heads up.
I'm assuming this means the thermostat is perhaps broken to the point where it is jammed, let's say, one third open? Just trying to grasp the situation.

Well, started her up today. After I turned it off, about ten minutes later, there was a small puddle of coolant under the drivers side of the engine block on the floor.
The timing belt and water pump were recently done by Mitsubishi. Mal, is there any chance that they have stuffed this up, causing an issue?
Will be ringing them up tomorrow none the less.

I am sure Mal will know better than me but is it possible a non genuine pump was fitted and only the genuine come with the biscuit cover ?. Dealerships do not always fit the genuine item.

I am sure Mal will know better than me but is it possible a non genuine pump was fitted and only the genuine come with the biscuit cover ?. Dealerships do not always fit the genuine item.

Yes, non-genuine was fitted (dealer preferred genuine but I went with non-genuine as it was $100 cheaper).
It is the brand repco sell. I am adamant they would have put on the appropriate items, though... the coolant and temperature has had no issues for 4000km.
Thanks for your input none the less!

I know when i had the 3.5 ltr Pajero done i insisted on the genuine being fitted as it was the only one that came with the biscuit cover, none of the non gen came with this. Being a Repco one i would imagine it to be GMB either in a GMB box or Tru Flo box.

Good luck with it, hope it is something covered under warranty one way or another.

I know when i had the 3.5 ltr Pajero done i insisted on the genuine being fitted as it was the only one that came with the biscuit cover, none of the non gen came with this. Being a Repco one i would imagine it to be GMB either in a GMB box or Tru Flo box.

Good luck with it, hope it is something covered under warranty one way or another.

Thanks steeler. Yes, hopefully it's under warranty depending on what it is!

The plot thickens slightly.
Turned the car on and drove it around to operating temperature after filling the radiator with coolant.
I left the car on and for ten minutes the temperature needled stayed on normal temperature (7/16ths)
The only issue is, the coolant is still dripping on the drivers side just behind the sump.
I can only assume this is coming from the water pump? I don't personally know the location and/or how to check it out properly. Any advice is appreciated.

Heat up pro black of coolant

As for using genuine because comes with backing, why? Nothing wrong with using good quality after market if done properly. Been doing these pumps since about 1999 and to date not aware of one which has leaked yet

I assumed that was the case. There was coolant in the overflow bottle... but the radiator took about 6-700mL of coolant before it got to the top.

Mal, any idea where the leak would be coming from, being on the drivers side just behind the sump?

I assumed that was the case. There was coolant in the overflow bottle... but the radiator took about 6-700mL of coolant before it got to the top.

Mal, any idea where the leak would be coming from, being on the drivers side just behind the sump?


Oscar, just coz it's dripping on the driver's side doesn't mean that is where the leak is coming from. The driver's side of the sump is the lowest point, so a slow leak from many places will run down to this spot before it drips off. I'd still be checking the seal on the water pump and all the hose connections if I were you.

Agreed, but after filling the radiator up again this morning and starting the car, I am sure that it is dropping from approximately an inch behind the sump. She's going in tomorrow so hopefully it's sorted out then at minimal cost.

Sounds like the pump mate, get mits to remove the covers and pressure test

Yeah will do. Thanks for the info Mal.

Turns out it is the water pump gasket. They should have replaced it when they did the water pump (duh?!??!!!) but they didn't.. so they should be footing the bill...
heh... should be...

No they WILL be footing the bill. What idiots not to replace a gasket.

I'd get the leak looked at first.

Has anyone tried the Davies Craig electric water pump and controlled and got rid of the water pump entirely (can ne done). Be interesting to see how much power you gain and fuel saved.
http://daviescraig.com.au/Electric_Water_Pumps-EWP115_Alloy___Controller_Combo__12V____Part_No__8 050-details.aspx

You would not be able to measure the amount of fuel saved as you would still need to run a bracket of some sort to run a pulley for the timing belt. Even then if you got around that the amount of power a water pump takes up for street use car is so negligible would be a waste of time and money. Perhaps if you were trying to set a land speed record is something worth while then again probably not.

Sounds like Oscar has had it looked at and the dealer have advised is the gasket leaking

Mmmn,
I fitted an aftermarket pump & fitted the gasket (block to pump, paper type) supplied with the pump. 32,000 km later gasket starts leaking. I ended up taking the pump out & fitting the Mitsubishi gasket & O ring to fix the problem. I'm thinking your problem they may have been caused by a non genuine gasket and possibly by the bolts being torqued/tightened without the threads being cleaned/lubed before reassembly.

Mmmn,
I fitted an aftermarket pump & fitted the gasket (block to pump, paper type) supplied with the pump. 32,000 km later gasket starts leaking. I ended up taking the pump out & fitting the Mitsubishi gasket & O ring to fix the problem. I'm thinking your problem they may have been caused by a non genuine gasket and possibly by the bolts being torqued/tightened without the threads being cleaned/lubed before reassembly.

Yes possibly.
The dealership just rang.

I am not 100% on the ball with what he said, but he stated that there was a crack in the housing of the water pump aswell. They got the new gasket on last night and it was still leaking.
When I purchased the pump originally I got the "half pump" which is the internals but not the casing. They have found the casing to be cracked aswell. They stated they are happy to supply me a full new genuine pump with gasket etc for the difference it would cost me originally (~$100) over the aftermarket half-pump. They stated they will be copping the costs of the labor and coolant. I find this to be fair.

Does this make sense or are they taking me for a ride? I will ask to see the cracked housing tomorrow when I pick the car up.

Sounds like a good deal. I'd take it!

Many other places would not have been as fair.

Sounds like a good deal. I'd take it!

Many other places would not have been as fair.

Seconded on that one.
For info on the 6G74's Mitsubishi do not have a parts listing for the gasket that goes between the two halves of the pump. They sell the pump as a complete assembly along with the water pump-block gasket and 35.1mm O ring

The deal sounds ok BUT in all my years doing these cars I have NEVER had a backing crack or seen one cracked and NEVER had the paper gasket leak either. If they used the proper sealant on the gasket to begin with and also torqued up the bolts properly this would not have happened. As for the crack, more then likely they over tightened the bolts which hold the 2 halves together and stripped these threads which is easy to do and this is where the issue started.

The deal sounds ok BUT in all my years doing these cars I have NEVER had a backing crack or seen one cracked and NEVER had the paper gasket leak either. If they used the proper sealant on the gasket to begin with and also torqued up the bolts properly this would not have happened. As for the crack, more then likely they over tightened the bolts which hold the 2 halves together and stripped these threads which is easy to do and this is where the issue started.

Fair enough..
It must have been the apprentice that did the job, then.
The head mechanic gave me the same spill.. saying he's never had one fail in the same way when placed on properly. He is equally surprised.
I don't think I'll be contesting paying for the rest of the pump, though. I've already given my word for that.
If they do try and hit me with any other chargers I'll give them a word.
Pick it up this arvo hopefully.. fingers crossed (blergh)