Jump to content
SAU Community

Recommended Posts

Ok so i have a rb25det neo in my 32 long story short some di*k tried to nick my rad cap and I didnt notice so car overheated bad head gasket went and compression as follows

1st cylinder 30psi

2nd cylinder 0psi

3rd cylinder 0psi

4th cylinder 60psi

5th cylinder 31psi

6th cylinder 121psi

engine was a 80000km import motor with a range of 150-147psi

so I got the head skimmed 25thou och

new gasket etc all torqued down

got a mate to do the timing (may still be out will be getting reset asap)

car wouldnt turn over

redid the comp test on the first 3 cylinders and gave up as the results where the same

there is no water in any of the cylinders so I know the head gasket is sealed

before I replaced it there was no oil in the cooling system or water in the oil

pistons dont seem to have shrink and pretty sure rings are ok

could the timing cause compression issues?

any other reasons this could be happening ?

otherwise I may just get the engine rebuilt or buy a long block (grrrrr)

Link to comment
https://www.sau.com.au/forums/topic/363610-low-compression/
Share on other sites

Timing can cause compression issue but it can't be that bad.... A cylinder might never be able to compress if one of the valves is open but if your timing is that far out, I would be surprised if you didn't bend your valves and they aren't sealing. Adjust the timing your self if you know how. Remove belt and slowly line up all markings to 0 degrees. Do a leak down test so you can source the leak. did you inspect the head when you replaced the gasket? Reading your thread over you seem to have over looked the head completely...

Edited by SargeRX8
Link to comment
https://www.sau.com.au/forums/topic/363610-low-compression/#findComment-5802198
Share on other sites

When I ripped the head off I got it skimmed and I checked all the valves etc and everything seemed ok (valves went up and down fine etc)

I didnt get it vac tested so im guessing it will be the head hoping not however :s

im taking it to my mates dad whos a mech and going to get him to set timing and do a leak down test to see whats up im guessing head will need to come off and be rebuilt or replaced

if it needs replaced id have to buy a long block as finding a neo head is near on impossible

Link to comment
https://www.sau.com.au/forums/topic/363610-low-compression/#findComment-5803694
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I'm normally copping my own abuse from neglecting my daily drivers. "Those suspension bushes will last a bit more", "Don't worry about the oil leak, just keep topping it up". The project cars I'm always doing things slowly on them as I'm wanting them to be done better, and neater, and nicer. Luckily I don't have to deal with 18 year old Matt's "Learning to wire" stuff in the project cars. And there's only one piece of wiring I'm displeased about in the Landcruiser, and it's about to be cut out... However, the box loads of parts that have been going through this place lately for the Landcruiser... Brake pads Brake Rotors Full handbrake overhaul Wheel Bearings Seals Swivel hubs Steering Boxes Half the suspension joints Shocks Air bags (Ones to go in the rear springs for towing) Water pump Timing kit Lower timing case Harmonic Balancer Radiator Lots of other little seals and shits Gas struts for the bonnet New power window switches And god knows what else I've forgotten... Ha ha ha I have my fingers crossed the pinion seals don't start leaking on the diffs, that the transfer case doesn't leak, and the gearbox input shaft doesn't leak, nor the rear main seal. As they're about the only seals I haven't replaced in the driveline! I'm seriously eyeing off buying new caliper rebuild kits front and rear brake calipers... I'll probably recheck all the valve clearances soon too, and hopefully, it should be all good and sweet to haul some long distance trips again!
    • Every time I pull my 3x gauges out of the console and see the crack-addict way that I did the wiring, and I just can't bring myself to tear it all apart and "make it nice", because it is currently working. In fact, the last time I was in there I probably made it worse.
    • The best part is when you own the car long enough that you look back and find your OWN ham fisted amateur shit!
    • The annoying part about neglect, is when you start to replace one thing, and find ten more broken things. Ham fisted monkey repairs you normally only find out about when trying to do something unrelated! Ha ha   Neglect you can kind of anticipate the huge costs to fix it all. Ham fistedness is normally a shock the first time your work on a new old car, as everything "looked" good before.
    • For DBA, check out their guide table here. https://dba.com.au/wp-content/uploads/2023/01/Direct_Replacement-Guide-2021.2.pdf   Additionally they have some other guides and info on how to make sure you choose the right pad.
×
×
  • Create New...