[Jack73343]

Hi Everyone, I'm new here and require some assistance from the more technically inclined individuals.
My 2014 Pajero Sport with 35k on the clock overheated when whifey travelled down to Durban a week ago.
The dealers reckon its due to head gasket failure.
Does a head gasket just fail, or it is normally as a result of overheating that a gasket blows?

The dealers are in the process of stripping the engine and doing tests etc to determine route of rectifying (Only gasket, new top, new block etc etc)so my next question is what are the typical other things that I can request from them to determine if all required parts were replaced or if necessary work was performed.
I basically want to educate myself in this whole process to ensure that I get a proper engine back. Ultimately I want them to replace my engine because its not suppose to do that after 35K, and due to overheating, some life must have been taken out of the engine, so I don't really want them to just overhaul selectively so I want some knowledge to challenge their way of establishing what to do with the repairs.
Sorry for the long post and thanks in advance for any advice or help.

[peterpot]

Manufacturers have the right to repair / recondition (cheapest option) and anything else they do do is goodwill - and goodwill normally depends on you and your attitude towards them - be honest and clear). It does sound as if they are giving you a good deal (new block, head, etc).

Firstly you are quite right a head gasket only blows as a result of ....
a) overheating (most common)
b) other factors such as incorrect fitment of cylinder head, uneven machine surface, overboosting, etc. (unlikely)

Let us assume for now it was as a result of the most common being overheating. If it overheated it must have been as a result of another host of possibilities. Starting with the most common .....
a) Loss of water ie water leak.
b) Lack of cooling air ( obstruction, viscous fan clutch failure, fan belt failure, etc.)
c) Mechanical (thermostat failure, incorrect fuel pump timing, etc)

As you can see it depends on preliminary findings which direction the matter will go. So keep us informed on what they find / report.

How hot did it get? ie Did it come to a stop or did your wife realise something was wrong maybe saw the heat gauge and stopped ? How hot it got will effect the extent of the damage and the extent of the repair. If it got very hot then the pistons will be damaged (score / scratch marks) and need to be replaced plus then the cylinder bores might have also been dammaged and then it will have to be bored and sleeved or bored and over sized pistons fitted. If the pistons are ok the rings might still have got hot enough to collapse. The cylinder head is a critical component that suffers the most in such cases. Most manufacturers would just hone or rebore the block, pressure test the head and refit. So if they are doing all you say they are (new block, head, etc - make sure they do. Some say one thing and do another - ie you would tell a new head from a reconditioned one) then you are being well looked after. note: if they do fit a new block the vehicle register / license details need to be changed - they would / should normally do that.

What is very important is that the cause is established. I would also recommend you get their ok on is to fit an Exhaust Gas Temperature (EGT) gauge plus a Cylinder Head Temperature (CHT)gauge with an alarm (Google MGL Avionics TC1 - it is a brilliant setup +- R2 500) to warn you (or the wife!) of any future / possible problems.

Let us know.

[Jack73343]

Thanks for the extensive reply Peterpot.
The car luckily didn't overheat to the extent that it seized. The wife just stopped at the Tollgate and saw steam coming out. I would have liked to go there and observe for myself the extent/cause but was unable.
After cooling down I asked her to crank the engine and it still started and according to her still idled smoothly.

I may have been misleading in my first post, but they have not yet committed to any repair strategy. So at this point I do not know if they are going to replace only gasket, or if only head, or the whole caboodle. The point I was trying to raise is how can I pressure them or challenge them on a technical level to ensure that whatever they do, I am left off in a good position.
Like if they say they will only replace gasket, then I want to know but what about the other parts of the engine that has been subjected to intense heat, that may have affected the integrity of say the rings, or bearings, that may still be within limits now, but because they have been subjected to increased heat, life has been taken out of them only to leave me stranded a couple of years from now. Are there any test reports, measurements etc that I can request from them to challenge the intended route.

[4ePajero]

Usually (but not always), a blown gasket is the RESULT of another problem.

If you don't find the CAUSE of the overheating, the new gasket/head/engine will suffer exactly the same fate.

Short list of possible causes:

• Radiator
• Thermostat
• Water hose
• Water pump
• Viscous coupling on fan
• Radiator shroud
• Coolant loss (expansion tank faulty)
• Incorrect coolant
• Blocked water passage in head/block

[peterpot]

Where are you based and which dealership is it at? ie is it at the dealership you normally service with / where you bought it ?

[Jack73343]

Where are you based and which dealership is it at? ie is it at the dealership you normally service with / where you bought it ?

I didn't buy the car new, bought it from a BMW dealership in Gauteng (Was traded in by previous owner). I've done approx. 10,000km since I bought it and standing on 35k so have only serviced it once in Empangeni on 30k, but my wife was on her way to Durban (Approx 130km from Mtunzini where I stay) and it overheated close to Umhlanga, so Mitsu roadside assist towed it to nearest dealership being Umhlanga Mitsubishi.

At least they offered me an ASX as loan car for the interim so the service has been good so far.
Am planning on giving them a visit to see what the progress is so far and what the plans are and will then also have a word with the dealer principle to see what we can get sorted.
Thanks for all the replies

[Jack73343]

Peterpot, I am quite intrigued by the EGT and CHT monitors that you mentioned.
How is the MGL Avionics system installed?
Is it simple thermocouples that you bolt onto the engine/exhaust or is it installed internally.
Who typically installs these type of units and I will look around here in my area. It will definitely assist in ensuring this doesn't happen again!

[peterpot]

The dash unit is the normal gauge size (52mm I think) and is mounted where you prefer. I don't like making holes and simply got an A pillar gauge mount. The gauge needs 12v which you can take from the fuse box right at your r/h knee. The temperature sensors probes are expensive R300 -R400 and they have to be fitted into the eghaust manifold (EGT) by drilling and tapping into the manifold and into the water / cooling system as well. Each is a thin probe (thinner than pencil) that has an electrical wire from the probe that connects to the gauge. I have seen thermocouple sensors that have an eye terminal that bolts on externally - I do not know how accurate / reliable they are by comparison.

[Jack73343]

Just an update on my ranting thread!
Where I stand 23 days later.
Visited the dealership on the 18th march, a week and half after the incident and they had only taken radiator out and done some tests to confirm head gasket failure. They also share with me that the vehicle had an engine block replacement somewhere in the 20,000km .
I was not aware of this when buying the car 4 months ago on 26k. I did try and do my due diligence properly and contacted my local mitsu dealer who conformed no major work has been done and that warranty and service plan was still in place. I should have checked engine number vs book before I baught but it never crossed my mind! Massive lesson learnt as I would not have baught the car!
Service book also had no mention of new block!

Visited again on 30 march, 3 weeks after incident, and again only radiator out, although the workshop manager said they took head off for test, refitted, put new thermostat and ran engine and again still overheated.
I flipped and lost it due to the slow progress and inconclusive answers on cause and plans on the way forward and walked straight into the dealer principle office for a firm but friendly chat.
He's not aware of my car but will follow up with the factory and service manager and get back to me.
Get a call this morning that they have been given the go ahead to fit new head
I want a new bloody engine considering that it is the second time on this vehicle in less than 35,000km that the engine went!!
I loved this car in the 4 months that I have had it but have lost complete faith!
I'm off to phone the service manager now for some clarity on the cause as it doesn't seam as if they know and only treating symptoms now!!

[4ePajero]

I'm off to phone the service manager now for some clarity on the cause as it doesn't seam as if they know and only treating symptoms now!!

Yes!