Non Mercedes - My Pajero 3.5 V6 Overheating

[brucemillar]

Oh God will it ever end?

My 3.5 V6 which recently had new head gaskets & water pump + radiator re-cored and all new hoses is again overheating. I have a calibrated aftermarket temp gauge which is reading 98-100 at motorway speeds and steam coming from the rad cap at a standstill.

I have no obvious leaks but do have a gurgling sound when the engine is running this seems to coming from the front end. I have a very audible squeaking/chirping sound at the front end.

This started today!

When I let it cool down, the header tank was empty and the rad took about 1.5 liters of coolant to fill up.

Started her up with the rad cap off and the within 2 minutes the coolant started to surge and gush up through the rad neck. Like she was burping but violent. We are talking volcanic spewing. This is continuous and pulsating as it pushes coolant up out the rad neck. If I replace the rad cap it pushes it into the header tank.

Any thoughts please.

Head Gasket?
Water pump?

I have no loss in power (yet)

 

[jotter22]

Bruce i think it's time for a gallon of petrol and a box of matches for this one....Donation's for popcorn supplies gladly received!

Tony.

 

[moonloops]

Last time I saw a car do that, there was a hole in the cylinder water jacket.

 

[grober]

The previous saga- for those who missed it.
http://www.mbclub.co.uk/forums/engine/195011-crank-position-sensor.html
Sounds like a CHG or cracked head- they crack between the valves evidently but could be several causes less serious . Time for a compression test perhaps? I notice no mention of thermostat renewal either? Can't remember if it was ever renewed right now?

 

[pembssurf]

Also could be something as simple as a decent size airlock.

 

[brucemillar]

Grober

Yes. Everything was replaced, and I do mean everything. We used all genuine Mitsi parts including the thermostat and rad cap.

Heads removed refurbished and skimmed
New head gaskets
New Water Pump
Cam Belt
Tensioners
Rad Re-cored
New Hoses
Stat
Temp senders
Gauge
Crank sensor & flag
Cam sensor
Ignition pack
Coils
Plugs
Leads
ECU
Wiring

Three weeks ago:

New exhaust
New Brake Discs and Calipers all round.

Considered "one of the best in the country" with a 3.6 V6 24 valve engine and very regular servicing running only top quality oil and coolant.

The cost of another engine (even if I could find one) will doom the truck. New heads (I suspect they will not skim any further off these ones) will also doom the truck.

We have to have a 4x4 for the winter here, as we live in the land of the single lane track and snow is not good.

 

[camerafodder]

Bruce the 2.8 (and the previous 2.5) diesel are infamous for cracking cylinder heads at or after 100K miles. Replacement heads aren't too expensive and are a modified design to prevent cracking. You can rarely see the crack and often it will not be apparent until the engine is warm. If you (carefully) remove the coolant reservoir cap and start it up, it will be bubbling it's merry head off. You'll also smell combustion gases in the reservoir.

EDIT: Sorry just noticed yours is a petrol. I have no experience of these

 

[HB]

Grober

Yes. Everything was replaced, and I do mean everything. We used all genuine Mitsi parts including the thermostat and rad cap.

Heads removed refurbished and skimmed
New head gaskets
New Water Pump
Cam Belt
Tensioners
Rad Re-cored
New Hoses
Stat
Temp senders
Gauge
Crank sensor & flag
Cam sensor
Ignition pack
Coils
Plugs
Leads
ECU
Wiring

Three weeks ago:

New exhaust
New Brake Discs and Calipers all round.

Considered "one of the best in the country" with a 3.6 V6 24 valve engine and very regular servicing running only top quality oil and coolant.

The cost of another engine (even if I could find one) will doom the truck. New heads (I suspect they will not skim any further off these ones) will also doom the truck.

We have to have a 4x4 for the winter here, as we live in the land of the single lane track and snow is not good.

Sell it on ebay, someone from North Africa will buy it.

 

[PobodY]

When my Nissan was doing something similar, it was a split hose on the back of the engine; didn't leak when it was cold, but once the system pressurised it squirted on to the exhaust (so no drips on the floor).

I just happened to hear it hissing when I was taking the wheels off and found it.

 

[toolman1954]

Start with a pressure test on the cooling system just to eradicate the obvious like hoses and joints. Then pull off a bottom hose and make sure water is being pumped around to rule out the water pump shedding its impeller.

Steve.

 

[grober]

Grober

Yes. Everything was replaced, and I do mean everything. We used all genuine Mitsi parts including the thermostat and rad cap.

Heads removed refurbished and skimmed
New head gaskets
New Water Pump
Cam Belt
Tensioners
Rad Re-cored
New Hoses
Stat
Temp senders
Gauge
Crank sensor & flag
Cam sensor
Ignition pack
Coils
Plugs
Leads
ECU
Wiring

Three weeks ago:

New exhaust
New Brake Discs and Calipers all round.

Considered "one of the best in the country" with a 3.6 V6 24 valve engine and very regular servicing running only top quality oil and coolant.

The cost of another engine (even if I could find one) will doom the truck. New heads (I suspect they will not skim any further off these ones) will also doom the truck.

We have to have a 4x4 for the winter here, as we live in the land of the single lane track and snow is not good.

You seem to have had bad luck with this truck Bruce. Toolman's suggestion of a cooling system pressure check is a good one. Likewise pump impeller failure. That drive belt squealing sound may be significant in that context. As per usual its just a question of going over the usual suspects one at a time in a process of elimination.

 

[markhgg]

Grober Yes. Everything was replaced, and I do mean everything. We used all genuine Mitsi parts including the thermostat and rad cap. Heads removed refurbished and skimmed New head gaskets New Water Pump Cam Belt Tensioners Rad Re-cored New Hoses Stat Temp senders Gauge Crank sensor & flag Cam sensor Ignition pack Coils Plugs Leads ECU Wiring Three weeks ago: New exhaust New Brake Discs and Calipers all round. Considered "one of the best in the country" with a 3.6 V6 24 valve engine and very regular servicing running only top quality oil and coolant. The cost of another engine (even if I could find one) will doom the truck. New heads (I suspect they will not skim any further off these ones) will also doom the truck. We have to have a 4x4 for the winter here, as we live in the land of the single lane track and snow is not good.

Have a look at rad cap, seem to remember from pajero owners club years ago that the right cap is marked as 0.9 on it.

 

[brucemillar]

Marhhgg may well be onto something here.

I let the truck cool right down. When I went to remove the rad cap (correct pressure 0.9) the rubber gasket fell apart!!

So I checked:

Oil dipstick = clean oil with no colant.
Oil Fill Cap = Clean with no coolant
Header Tank = Clean with no oil
No excessive steam or drips from exhaust.

So I put 2 liters of clean water into the rad and started the engine with he rad cap off:

No bubbles!!

Waited for the start to open (about 85 on the gauge) it is an 82 stat. Watched as the water visibly moved across the rad. Still no bubbles or burping and I had the nose of the truck point uphill.

Left it running at idle for 30 minutes and all is fine. Fitted an old but reasonable looking rad cap. No coolant pushing out into the header and no steam. Temp stayed at 85 with he engine idling for another 20 minutes.

Ran out of time to test and had to leave it. Next test is to run it up the road.

Please pray to your God that it is a bad rad cap. I need some luck here.

 

[markhgg]

Marhhgg may well be onto something here. I let the truck cool right down. When I went to remove the rad cap (correct pressure 0.9) the rubber gasket fell apart!! So I checked: Oil dipstick = clean oil with no colant. Oil Fill Cap = Clean with no coolant Header Tank = Clean with no oil No excessive steam or drips from exhaust. So I put 2 liters of clean water into the rad and started the engine with he rad cap off: No bubbles!! Waited for the start to open (about 85 on the gauge) it is an 82 stat. Watched as the water visibly moved across the rad. Still no bubbles or burping and I had the nose of the truck point uphill. Left it running at idle for 30 minutes and all is fine. Fitted an old but reasonable looking rad cap. No coolant pushing out into the header and no steam. Temp stayed at 85 with he engine idling for another 20 minutes. Ran out of time to test and had to leave it. Next test is to run it up the road. Please pray to your God that it is a bad rad cap. I need some luck here.

If you put a condom over the open neck of radiator, see if it inflates, means gasses getting into water, not good. Make sure new cap is 0.9 bar and not 1.1

 

[Codger49]

Be sure to check you have removed all traces of white feathers first though!

 

[brucemillar]

I can't believe I'm saying this on a car forum!

I have no condoms. Can I use a plastic bag?

 

[markhgg]

I can't believe I'm saying this on a car forum! I have no condoms. Can I use a plastic bag?

lol no in short, if you do a search for pocuk it is a great forum, the guys on there will help you, I used to own one many years ago .

 

[grober]

I would suggest before going down the "prophylactic route " just try a decent/ new radiator cap. The fact the seal fell appart would suggest you have found the culprit??

 

[brucemillar]

New cap ordered from GSF for collection tomorrow am.

The previous one was a Blueprint one. Not sure what this is but for £9.50 it will prove a point and maybe save my truck.

 

[grober]

SERCK used to be a leading aftermarket supplier.
http://www.serckautomotive.com/wp-content/uploads/2016/08/Serck-Brochure.pdf