2008 2.8 Crd - Engine Problems

[CoxynotKirsty]

Purchased a 2008 2.8 Diesel Limited recently from an auction for a very low price with expectations of engine issues - it has 275000 kilometers on clock.

 

Starts well, has a slight miss but has poor acceleration and appears to be slipping. 

 

Initially took it to a Diesel Diagnostics for compression test (but not wet) and gave numbers of 400, 400, 340, 320.

We sat down and decided it was rings and probably a new engine - totally convinced me not to contemplate a rebuild.

 

Then went to one of the few independent Jeep/Chrysler people in Melbourne. They happen to have a 2012 engine with 40K on the clock so took the car in today so they could look at it in anticipation of doing an engine swap and they tell me they couldn't find anything wrong!

 

So it got me thinking............

 

Its down on power - I also have a 2008 3.8 petrol (the diesel is a project) and the power is nothing near as good.

 

When I quizzed the first guy about the engine I asked about collapsed rocker cams and he said that the compression in the cylinders would be high, not low (they tend to fail closed) which made sense - as we assumed it was rings.

 

But what if we got it wrong - the normal cylinders were pushing 340 @ 320 psi and it is cylinders 1 and 2 are the problem.

 

So now the questions

 

Anyone done a compression test on the 2.8 and if so, what numbers did you get. 

 

Anyone dropped a rocker arm and, if so, how did it manifest itself?

 

Thanks in advance

 

Coxy

 

 

 

 

 

 

 

 

 

 

[lessuth]

Does your slight miss normally happen when you are starting off and if you remove your foot from the pedal and reapply it the miss has gone? 

Are you sure the trans is slipping? Could it be a manifestation of the "miss" as the engine does not stall but just seems to "starve" for diesel?

These diesels seem to need a minimum of 650 CCA to 800 CCA and have a good charge rate or can behave in the manner I have just described.

I have seen the fuel pressure regulator valve give a similar fault.

[karmannski]

I will try to check, 3 out of 4 Cyl as I cant be bother of removing alt to get in to the 1st plug. Sorry but I'm going away in few days for holiday. 

 

And I recommend to use some diagnostic equipment to read faulty codes from ECU that will help us to focus on the right stuff. 

 

It could be anything. 

 

- bad fuel 

- bad injector

- low pressure (normally wont start or will cut off)

- MAF Sensor need replacing (try to borrow one just to test it)

- bad timing? If cam-belt was done and timing not set right will have to check that. 

 

 

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