Possible blown motor

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Possible blown motor

Postby Speedy70 on Wed Jun 05, 2019 7:57 pm

Hi All, I'm looking for some advice on a potentially blown 2014 MN 2.5TD motor. My car has done 150,000Klm. The original motor was replaced at around 27,000klm under the cooling system campaign due to overheating, with a brand new long motor.

About a week ago I was driving to work going up a hill at about 100 kph (vehicle was unloaded with just me it) when it lost power and started blowing black smoke from the exhaust. There were no bangs or loud noises when this happened, just a loss of power and the smoke from the exhaust. I coasted the car down the other side to a service station and shut down the engine. I have an OBD2 reader which gave me an engine code of P0304 - Cylinder 4 - Misfire Detected. Once restarted the engine ran very rough and did not rev well. I had the car towed to a mechanic who did a few tests and his opinion is that a full rebuild is required ($11.5K). He did not remove the head but was confident that it would need a full rebuild from his experience with these engines. He did say that a pressure test of the radiator indicated a head gasket leak and it was running on 3 cylinders. I still need to get a report from him on the tests carried out. Intake/intercooler pipes were not leaking and no load noises when this happened (I have had the turbo to intercooler pipe split before so I know what that sounds like).

This motor was running fine up until this point. The only things that I had noticed recently was that it was blowing some black smoke on take-off. It had no overheating issues and did not suffer any of the symptoms I encountered with the original motor (varying coolant levels etc.).

Has anyone else had a similar experience to how this engine failed? I was thinking possible blown head gasket or injector, but not a total rebuild, especially considering that this was a replacement motor. Any advice would be appreciated. My next step will be to get a mechanic to remove the head so the problem can be properly diagnosed, but just curious as to whether this kind of issue has happened to anyone else and what the problem was.

Cheers
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Re: Possible blown motor

Postby Longranger1 on Thu Jun 06, 2019 1:26 am

I would be sceptical of an instant diagnosis saying you needed an $11+K rebuild without first removing the cylinder head. It may be that all it requires is considerably less work.
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Re: Possible blown motor

Postby MilkmanDan on Sat Jun 15, 2019 10:01 pm

Before ripping the motor apart and spending money get another opinion. Think how a diesel works, could be a dodgy injector?

I know could be a hassle moving it around but 11k is a lot of coins on one opinion
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Re: Possible blown motor

Postby stefanos on Sun Jun 16, 2019 12:55 pm

Take a look at the injector first off all.It's impossible a head blown gusket not to effect on cooling system!!
If your car ecu read this fault,99% your injector is usseless.I take out my injectors for cleaning and testing and the 4th was useless according to the test machine but I haven't any fault yet!!May be the ecu reads fault when is 100% useless.The other 3 with thw cleaning was ok
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Re: Possible blown motor

Postby gspy4u on Sun Jun 16, 2019 5:46 pm

I'd be doing some of my own checks first before handing out 11k.

Is the oil contaminated ? Has the coolant level gone down in radiator or is also contaminated ?
Is it a faulty or damaged Crankshaft Position Sensor ?
Check the engine oil (drain it) see if contaminated and then maybe take the rocker cover off and see if there is any telling signs (sludge etc from coolant contamination). It may be a pain but description doesn't really sound like head gasket at this stage.
You could always take out the injectors and have a look at them as well. If it is reporting cylinder 4 then i would start with there.
Take it to a diesel specialist if you can't do the checks yourself.

Code P0304 is a fairly broad code that could be caused by a number of things but it is pointing to Cylinder 4.
I'd start at simple things like crank sensor, check it, check wires maybe clean it and then work from there.
If you clear the code does it run fine or does it sound rough and comes back ?
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Re: Possible blown motor

Postby Speedy70 on Tue Jun 18, 2019 5:54 pm

Thanks for the responses. I've checked the engine oil and coolant and neither seem to be contaminated and the coolant level is OK. The mechanic said that he checked the injectors and they were OK.

When the engine is running (very roughly) and I take the engine oil filler cap off, there is heaps of smoke coming out. There is also lots of smoke from the exhaust. I would say it is whitish but it does smell like burnt oil. The engine is definitely only running on 3 cylinders. From what I've read, this could indicate a holed piston or excessive ring damage. The engine failed suddenly, so I don't think it would be worn rings.

I also don't think a failed injector would result in smoke coming from the the oil filler cap. Could a worn/ broken valve or a cracked head result in this happening?

I put a head gasket sealer through it to see if it did anything but no joy there (I didn't expect it to work but thought it was worth a try and was hoping that if there was some improvement it may have indicated or confirmed a head gasket issue).

The car had codes P0201, P0203, P0204 and P2146 in addition to P0304 when it came back from the mechanic, I presume from him disconnecting and testing the injectors/injector system. I have cleared the codes and have not had any codes/engine check light on restarting and letting it idle.

It's parked up now until I get the time to organise a 2nd opinion, but still interested in any feedback on the above. Cheers
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Re: Possible blown motor

Postby Intruder on Tue Jun 18, 2019 8:28 pm

Strongly suggest you go to the Forum Directory at the top of this site and follow the link under Manuals so you can download the MN Triton workshop manual.

Then search the manual for the original error code (P0304 you stated). Mitsubishi is very specific on what that code is, its not the generic "misfire code" you get by Googling the code your generic OBD-2 reader gave you.

Mitsubishi Workshop Manual clearly states the following for Error Code P0304:

"CODE NO. P0304 NO. 4 CYLINDER INJECTOR MALFUNCTION (NO INJECTION).

PROBABLE CAUSES
•Failed No. 4 injector
•No. 4 fuel injection pipe clogged
•Failed Engine-ECU"

From there if you can't do the fault finding listed in the manual yourself, get a specialist diesel mechanic or Mitsi to do the diagnosis for you. I'd personally get Mitsi to do the diagnosis at least so it can done properly with their MUTT-3 diagnostic tool. You don't have to use them for the repair, that's your call but at least you can get specific quotes from other places and compare apples with apples.

Your first mechanic seems to be leading you up the garden path in a shocking way with that diagnosis and without actually removing anything to provide evidence of their claim is criminal. You also seem to be looking for issues not related to the actual original code thrown and looking for worse case scenarios that are not related to the issue. So based on what's in the service manual, you're hopefully not seeing a full engine rebuild in your future as long as you get the actual issue rectified and not chase shadows and let the real issue lead to other problems.

Good luck with it.
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Re: Possible blown motor

Postby aids84 on Wed Jun 19, 2019 1:55 pm

A misfire could only be caused by a dud injector (including the control circuit) or low compression in that cylinder. I suggest disconnecting the injector plugs and then cranking the engine over. You should be able to hear if one cylinder is low on compression while under cranking.

There isn't really an easy way to do a proper compression test on these engines. The glow plugs are pretty inaccessible with the manifold design and the rocker cover has to be removed to use the injector holes.

Low compression is going to be caused by either a cracked/holed piston, a valve issue or a head gasket problem. The head will have to come off no matter which it is.
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