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Rebuild or not a overheated engine

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Hi guys

what you think about rebuild a overheated engine dont know how bad it Been overheat

engine is a rb25det

any tips. Thing to Check deck straightness etc.


Hello I would recommend you pull it apart and ask a machine shop to hardness check the cylinder head

if you also ask to have the block and head checked for straightness if it passes the first test

the conditioner would be the best guys to advise on where to go from there but at the most, you may lose a few days pulling it apart and getting some good experience

Regards Ross

I assume this is not originally your engine?

Not knowing if it was simply blowing vapour out of a weak pressure cap, or full thermo-nuclear melt down, it is difficult to say.

If the engine is complete, there are a few things that can assist before pulling it down - have a sniff at the fill cap to see it the oil smells burned, do a compression test or, preferably, a leakage test - the latter will identify where any leakage is by listening at the exhaust, intake, filler cap and, if the engine is in the vehicle, bubbling or blowing out the collant filler.

If you decide you need to take the engine apart, or at least check the head gasket, pay attention to how much torque is required to crack the various fasteners loose, especially the head'. If they are about equally tight it suggests there is unlikely to be a major problem, but if some are looser than others it suggests a gasket failure at those places - make a note for further checking.

When the head is removed - NOTE, if there is a block drain, USE IT, it makes things much less messy and easier for diagnosing without coolant everywhere - look at the valve colouration, the piston crown colour, and for any scuffing or discolouration of the bore as that suggests piston or ring scuffing.

When you flip it over and drop the sump, have a good look over the main bearing girdle/cap areas and the big ends for any colouration differences that may indicate they were running hot and note them for further checking.

When you remove them, check the pistons aren't showing signs of scuffing or ring wear - especially if there are bore markings.

As Ross said, when you're having the head checked for warping or cracks, also have the hardness checked - if it got hot enough the alloy may have lost hardness.

Thanks for your answer

no it’s not my engine i buy it with some other part i plan to pull it apart ans get experience ans find if it any good to rebuild

thanks again!