No.4 cylinder overheating

[Jay762]

This has stemmed from another thread - thought I would start a separate discussion though.

 

Is overheating and subsequent failure on No.4 cylinder a common issue on EJ20 or EJ25 engines and if so how would it be prevented on:

 

a. standard open engine blocks

 

b. semi closed engine blocks

 

c. closed engine blocks - although I am assuming it does not affect the closed blocks at all

[Adam]

Its a fuel delivery issue so the block design isn't part of the problem. The cylinder is last in line in the fuel rail so can sometimes run lean and as the petrol vapor helps cool the piston it gets hot and melts. Depending on how much you want to spend, upgrade fuel pump, fit a new fuel pressure regulator and get the car mapped to give the correct fuelling for the above. The next step if you have the funds is to fit a parrellel fuel rail system.

[Jay762]

Excellent thanks Adam

 

Is this pertinent to EJ20 and EJ25or just EJ20?

[Adam]

All EJ20 engines.  It's not so much a design problem, it's more likely one of two things... An old age problem when things like the fuel pump get weak over time, or a bad tuning problem where other mods put demands on the fuel supply that they were not designed to handle. 

[Gambit]

Yep Will say thanks too some great information. Only down side is it's now got me looking at fuel pumps and other parts for the car :D

[Adam]

The mapping is the most important part in that chain as it will show up any problems elsewhere, and if they are small it can compensate for them.  If they are not small you will go away with a shopping list for any new parts that are needed!

[Gambit]

I would have it mapped anyway I had a full engine rebuild and some extras added about 58k miles ago now, it was mapped to 360bhp but when fuel prices got silly I went and got it remapped again to 300BHP Not that I've seen a great deal of difference mind :D