Redcat,
The 4e-clan is a huge asset to this really nice and friendly forum. I have to agree with you on this one.
Thanks 4e-guys.
Roelf
Affiliate Member
One very important point not mentioned regarding failure of the shafts is the run up and run down of a turbo. On a Cold start the engine takes a bit of time to build up proper oil pressure and for that short while the turbo runs without adequate lubrication, the oil does not reach operating temp straight away and the efficiency is not 100% and therefor the run up time on a turbo. On turn off the turbo can be extremely hot after running and remains that way for a good 2 -3 minutes, this heat is transferred to the oil and if you shut the engine off too quickly the oil around the bearing shaft of the turbo burns, not flames, but rather cooks leaving a carbon residue in the bearing space. This would leave the same marks as in the dirty oil pictures. Allowing the engine to idle for 2 min after driving helps to cool the turbo and lets the oil conduct the excess heat from the turbo bearings.
On a normally aspirated engine quality oil is important and on a turbo engine it is 100x more important and at the risk of sounding like one of the 4es if you are not running dello on a turbo diesel there is room for improvement
On a normally aspirated engine quality oil is important and on a turbo engine it is 100x more important and at the risk of sounding like one of the 4es if you are not running dello on a turbo diesel there is room for improvement
Henk Bannink
Some people are wise, some people are otherwise
Some people are wise, some people are otherwise
Henk,
I agree with the cooling off of the turbo by letting the car idle for a little while. Most of us, however, live in a city environment and I should think that it is not always necessary. Let me explain: I come home from a weekend-away and about ten kilos from home I get into the city and suburban traffic and start to slow down and sort of idling all the way home. Surely this will be enough time for the turbo to cool down?
I agree with the cooling off of the turbo by letting the car idle for a little while. Most of us, however, live in a city environment and I should think that it is not always necessary. Let me explain: I come home from a weekend-away and about ten kilos from home I get into the city and suburban traffic and start to slow down and sort of idling all the way home. Surely this will be enough time for the turbo to cool down?
CATS
Your question about the EGT's
I must apologize for mentioning the three Pajeros with turbo failure under this heading "3.2 DiD", I discovered last night they were the older 2.8's. The cause of the turbo failure on these Pajero's were too high EGT's, damaging the exhaust side of the turbo. In one case even cracked the manifold. All three were working hard, towing caravans from the coast. They did not break down, power dropped and excessive smoke were the only signs.
Your question about the EGT's
I must apologize for mentioning the three Pajeros with turbo failure under this heading "3.2 DiD", I discovered last night they were the older 2.8's. The cause of the turbo failure on these Pajero's were too high EGT's, damaging the exhaust side of the turbo. In one case even cracked the manifold. All three were working hard, towing caravans from the coast. They did not break down, power dropped and excessive smoke were the only signs.
Martin Bouwer
2018 Pajero DiD LWB Exceed
2017 Triton 2.4 DC
2015 Pajero DiD LWB Exceed - Sold
2005 Pajero DiD LWB GLS - Sold
2008 Echo Kavango
2018 Pajero DiD LWB Exceed
2017 Triton 2.4 DC
2015 Pajero DiD LWB Exceed - Sold
2005 Pajero DiD LWB GLS - Sold
2008 Echo Kavango
This is part of the learning curve. I know zilch about turbochargers except the normal thing that it boosts power and that an over temp can / will ruin it. Continue with the expensive lessons and if and when the real cause of the failure is known, pse inform the rest of us and also make suggestions on how to prevent suc an occurance.
I have two comments to make:
1. The damage must have been caused by some foreign body - a nut or screw. I do not think sand grains will / can cause that much damage - it will grind the blades away.
2. The silicon sealant visible in the one photo seems like an "after market" job and not as a factory (Mitsubishi) will use sealant.
Cloyd.
I have two comments to make:
1. The damage must have been caused by some foreign body - a nut or screw. I do not think sand grains will / can cause that much damage - it will grind the blades away.
2. The silicon sealant visible in the one photo seems like an "after market" job and not as a factory (Mitsubishi) will use sealant.
Cloyd.
Affiliate Member
At full boost a turbo runs between 220 -250 000 rpm 
it sounds unbelievable but it is true, at those speeds the slightest debris would nick the impeller blades and cause it to look like the pics any bigger bits like a nut would totally destroy the turbo and probably snap the shaft as well. I tried to ceramic coat the piston tops in attempt to shield them from heat in one of my toys against the recommendation of the engineers, the result was that the exhaust side of the turbo looked like the pics as the ceramic coating cams off in bits and pieces due to different expansion characteristics of the compounds
The result was not catastrophic failure but the unbalanced impeller put more strain on the bearings and the vibration limited the efficiency of the turbo and it lost boost and smoked like a naughty teenager behind it's fathers back.
Silicone sealant does not like petrochemical compounds. Exposure to oil or petrol results in a gwabby mess like in the picture. That example probably started as a small bead of excess silicone compressed from the mating surfaces and with the constant exposure to the oil draining from the turbo tuned in to the mess seen in the pic. On that joint there would probably have been a paper type of gasget and a bit of grease would have been a better sealing compound if something like Hermetite was not available. Another dislike of silicone or RTV is contact with aluminium. Often folks put a dab of silicone to seal a radiator hose or thermostat housing, it works well.... for a while .....until the acetic acid in the silicone starts to corrode the alu housings.
it sounds unbelievable but it is true, at those speeds the slightest debris would nick the impeller blades and cause it to look like the pics any bigger bits like a nut would totally destroy the turbo and probably snap the shaft as well. I tried to ceramic coat the piston tops in attempt to shield them from heat in one of my toys against the recommendation of the engineers, the result was that the exhaust side of the turbo looked like the pics as the ceramic coating cams off in bits and pieces due to different expansion characteristics of the compoundsThe result was not catastrophic failure but the unbalanced impeller put more strain on the bearings and the vibration limited the efficiency of the turbo and it lost boost and smoked like a naughty teenager behind it's fathers back.
Silicone sealant does not like petrochemical compounds. Exposure to oil or petrol results in a gwabby mess like in the picture. That example probably started as a small bead of excess silicone compressed from the mating surfaces and with the constant exposure to the oil draining from the turbo tuned in to the mess seen in the pic. On that joint there would probably have been a paper type of gasget and a bit of grease would have been a better sealing compound if something like Hermetite was not available. Another dislike of silicone or RTV is contact with aluminium. Often folks put a dab of silicone to seal a radiator hose or thermostat housing, it works well.... for a while .....until the acetic acid in the silicone starts to corrode the alu housings.
Henk Bannink
Some people are wise, some people are otherwise
Some people are wise, some people are otherwise