Mi16 engine not starting after rebuild

[DamirGTI 342]

Probably the rings stuck to the piston/piston grooves from standing so long and dry/without oil/lube ... if they where new rather than worn .

 

Might try to "unstuck" them by filling the cylinders with diesel , mixture of Xylene and Acetone (bit thin as an fluid/chemical mixture , but does wonders for melting carbon deposits)  , mixture of ATF and Acetone , or similar ... leave for a while and spin by hand few times in a few days .. then drain and dry out the cylinders and see if the compression goes up a bit , if it does , try to start it .

 

Depends what's happened/made them stuck , carbon or rust .

 

D 

Edited November 10, 2021 by DamirGTI

[davemar 16]

I did remove the pistons from the liners, and the liners from the block before I refitted the engine to give them all a good clean up. So the rings were all moving freely as I had to rotate them to get the gaps 120 degrees apart. There was a bit of rust in the liners, but very much just a light surface dusting rather than anything nasty. I wonder if there was something I did wrong with the rings when I originally fitted the rings all those years ago, or the liners are just too worn.

 

 

[SweetBadger 94]

I agree, sounds like it's going to have to come apart.

 

If the liners are not lipped at the top and the rings new, then just get the liners properly honed, verify the rings are correctly installed and bolt it back together - I can recommend Gardias Engine Services for honing the liners, they have done similar work for me to a really good standard inc decking an MI block and liners. If you can feel a lip at the top of the liners then it's new liner time.

 

Before you do, how confident are you in the compressions tester you are using? I have one that I bought new and it reported 180psi on my rebuilt Gti6 engine. When it was being mapped a decent snap-on gauge read 260psi across the board! So it was reading a whopping 44% low. Maybe do a quick compression test on a known good engine to verify the tester accuracy before pulling it all apart just in case.

 

 

Edited November 11, 2021 by SweetBadger

[welshpug 1,657]

did you clean the rust off?

[davemar 16]

Yes, I cleaned the rust off.

 

The performance of the compression tester was a concern. My other car is a Subaru Impreza (which has been annoyingly unreliable over the past couple of months too!), but getting a compression tester into those is really difficult as the spark plug holes are low down and right up against the sides of the engine bay.

 

[Richard309Sri XU5JA 205GTi 8]

what make are the "old"  ones? 

 

I know Goetze are well known but I actually used some Mahle ones and they have been great so far. 

 

Take it the Mi16 is the same spec. as the 1.6 and 1.9gti? 

 

I used a three arm honer and it seems to have done ok. 

[SRDT 175]

Peugeot machined the original J4 liners like the other ones, probably to save on tooling costs. It's on the outside that they got creative:

[davemar 16]

The ones currently in the engine look like that with the ribbing, so are probably original XU9J4 ones. However, the ones that were in the engine before (when it was running fine) don't have the ribbing, so maybe originate from an 8v engine? I've had both engines for such a long time I struggle to remember what their history is now. 

 

I've just starting taking things off the engine this afternoon and the inlet manifold had a lot of oil in it. That's obviously just accumulated from spinning the engine on the starter several times, and not from the engine actually running. So something is clearly not right with it.