GTO TT Engine, can it be saved


A bit gutted to post this but here we go.

My name is Angel, I’m from the West Midlands UK. I’m not new to restoring classic jap cars, I have restored an MR2 and a Celica both 1992.
I have purchased a 1992 GTO Twin Turbo 5 Speed Manual that didn’t start (not even cranking).
The engine turned by hand (crank pulley), so I decided to check and repair the starter (it prooved to be unrepairable so I bought a new one).
It cranked fine, so I bought a new battery.
The engine still couldn’t start so I diagnosed all possible things:

  • ECU caps, surely leaked and replaced them along with repairing the copper trace next tot the C6 SMD.
  • Refurbished the ignition system (as it didn’t fire on plugs 2 and 5)
  • Replaced the fuel pump with a Walbro
  • Replaced the fuel filter, replaced the IACV as well, as they are prone to damaging the ECU.

Engine started and ran on all 6 cylinders, even managed to move the car on the parking space.

I then decided to check the timing belt , which has seen better days but it wasn’t snapped.

Now the timing marks are as on the pictures.

I have used an endoscope to have a look on the front bank of cylinders/pistons. Didn’t look at the rear bank, but I will, as soon as the sky clears and there’s no more rain.

Here is the link to the video:

What would be the best approach to save this engine? If it’s possible to save it.
Thank you all :slight_smile:

I would get the engine all timed up checking the bottom crank gear - you will need to remove the crank pulley to do it properly.

I would then check tension of the belt and also compression of the engine.

This is the only way to see how bad the engine is - if it’s a TT and you get a PSI around 150 (I think) and all 6 are within 14 PSI then your engine is good. Low compression and lots of rattling and more diagnostics will be required.

If the engine skipped time only on idle you might be ok.

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Will it be a good idea to buy this timing kit?

I couldn’t find anything better in the UK

Robs kit at EE is certainty a premium kit and has been used widely by many GTO owners in the UK and also comes with cam lockers and timing tension tool (not mandatory but can make the job easier). Rob can also take time to get things delivered so if you’re in a rush best contacting him directly to get current lead times. There are other supplier’s and cheaper options available to you as well.


Rear bank looks off. Is it running rough?

quite rough.
Honestly when I sorted the ECU, fuel and spark, it was running fine (not perfect).
Then, after that, I took the timing cover off (front bank) to inspect the timing belt.
Started it again, and i saw how big the slack of the belt was when running , it was deflecting 0.5 - 1.0 cm up and down between the intake and exhaust cam pulleys :open_mouth: and it was sounding quite rough. i stopped the engine, and didn’t start it again.

The marks on the pistons are quite new (shiny) - so I would say it only happened during this small amount of time (after i took the front timing cover off).

Anyway, I will do the timing again, using the 3 part youtube videos on the @3000GTGTORestoration channel (massive shoutout, absolutely spot on video ! :slight_smile: )

During times like these, I would really want to have a garage… but I’m going to do the job on the driveway, as I always did with the other classics :smiley:

Will update on this along the way
Cheers :slight_smile:

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I think once you get the timing reset it will be OK. Hope all goes well.

I had ordered the timing kit from EvilEmpire, I believe I will have a phone call as the order is still in processing status since Thursday.
I had some time during the weekend to take out the intake plenum to check for the rear bank pistons and they seem to look fine, it didn’t touch the valves.
Here is a video of how it looks:

From what I see, only the front intake part was a bit affected.
At this moment I am preparing for the timing belt kit by removing all the bits and bobs necessary for this operation.

Update :
I have installed the full timing kit (got it after almost 1 month :slight_smile: )
Tested the compression of each cylinder.

Mind you, this test was done on a cold engine, as the throttle body, intake plenum, spark plugs are out.
Also took out the fuel relay just so it doesn’t turn on the pump and inject petrol in the cylinders.

Results :
1 126
2 125
3 95
4 130
5 113
6 124

What would be the best approach now?

Thank you

Do the same test again and drop some oil in each cylinder and see if the compression reads higher if so ots piston rings but also you should do a leakdown test to see if its also valves not sealing properly