The EZ and AAM have oil gallery trough connecting rod, GU does not. If i reuse the GU pistons should i keep the rods too or replace with aam or ez ones? Perhaps they help cool down piston crown, if oil squirts up the top.
Well, i am very disappointed. One problem remains from before, the nasty start/misfire+knock at startup(fuel knock), and possibly pinging over 20% throttle. I an not sure about pinging because i never heard it before. I tried setting the timing at diamond tried advance, retard, the noise remained. I used ABS 1.8 mk3 pistons which were the same as 1.8 GU. To lower CR i may have to put the AAM pistons. After i opened the choke flap started right up.
hmm. Maybe go back to basics double check the cam, crank and distributor timing is correct, pics here obviously ignore the setup procedures: https://clubgti.com/forums/index.ph...nose-and-tune-your-mk2-digifant-gti-8v.124949 Also check over your 2e2 carb carefully, you may need to change the jets now you've upped it to a 1.8 and put a nice cam in. I'd start with a 1.8 2e2 carb for a base: https://clubgti.com/forums/index.php?threads/1-6-1-8-pierburg-2e2-carb-faq.124945/ with the distributor was it the original 1.6 you've got or did you find a kjet GTI one? I'd only use bosch ones also, the aftermarket ones can be made incorrectly
Its original dizzy. Timing is good. Advance set with timing light. Now did not start with choke flap opened, same as before, start fine runs fine for 5s then dies/misfires/sputters and cranks like no compression. Cam followers seem a bit tight. Im using 15w40 castrol.
Hehe. Might be onto something. My diesel compression tester pegged at 10-15bar/150-200psi oil pressure! 200 psi at 1500rpm, any higher the engine stalled from lack of compression. Those lifters are stretched!! Most likely the pressure relief in the oil pump is stuck shut, and 200psi of oil pressure is making all sorts of problems. Saw some oil through the spark plug hole on the piston, either from high oil pressure (not likely) or the rings need bedding in.
Sure enough, relief valve was stuck shut with bearing pieces all over. I replaced the oil pump and the cold start havoc is rezolved, however the clicking/pinging sound remaines.
good progress with the carb distributor the stock timing is set to 18 degrees BTDC with the vacuum line to the distributor connected. if using the diamond on the flywheel it needs to be a carb one with 18 degree mark, the GTI one is set at 6 degrees. If you compare the flywheel picture in my digifant thread above you shouldnt be able to see the TDC marker when the diamond is in view
Yes i have tried 18 degrees, more and less, the noise is the same. I have the original flywheel too. I have a full tank of 95 octane, maybe i will try some 98-99 to see if there is any change.
What i changed in the second repair attempt besides pistons, was the flex pipe. It could be an exhaust leak. But, exhaust manifold was cracked, flex pipe cracked and never heard any ticking noise. I will check for exhaust leaks and if there aren't any, check replace tappets and camshaft.
Tappets can take 1 to 3 secs to fill after start up, giving you a tapping noise. On first build , first run they can take 10 mins! at fast idle. Jon
Today i removed and dissasembled all tappets, they were fine. Did a compression test, little over 115psi on all cylinders. Still a lot of oil on top of all four pistons. So far oil level did not drop, in 260km since repair. Spark plugs look good. It cannot possibly be pinging at 115psi compression pressure. Ring gap was 0.40-0.45mm, bores were good, i dont know why compression is so low. Broke the outlet of the waxstat, and the thing comes only from vw and is not cheap, its almost as much as a used whole mk3 golf engine. I tried superglue and some 2 part glue but did not hold. Now I tried some rtv. Im getting tired of this car really. Should have left it as it was. Engine was in very good shape.
oil on top of the cylinders could point to valve stem seal failure, and/or worn valve guides waxstat is part number 026129243 replaced by 026129243C, I see several on ebay plus various UK retailers for around £80, expensive as you say but not too bad. Though its around the cost of a weber conversion so you can see why people give up on the 2e2 as they're getting expensive to keep running
Before rebuild never had an oil problem so valve guides should be good. Also I replaced stem seals with new elring ones, and when I removed again the head checked a few valves and were dry. I found a local guy who has a 2e2 for half the waxstat price and will get that for spares. Did some diy leakdown(put air pressure on spark plug hole) and only heard espaping air from rings. Have done some 0-140 km/h times, it about 1s better on 0-100, and 5 seconds 0-140km/h, this with a very low compression. Hope it will improve. That ticking sound drives me crazy, i really hope this goes away as well. While diagnosing ticking noise i tried 1 tooth advance and retard the camshaft and again did nothing to the sound.
I went on a 700km roadtrip to see what she does, and she lost compression on cyl 1, its about 2 bar, the rest remained at 8 bar. Still has oil on top of piston. Guess Will open her up again. I put some pressure on spark plug hole and confirmed it looses to the sump.
You've not got a lot of luck recently... With 30psi compression, you should find the problem real easy.. Rings can get broken as the piston goes into the bore, on assembly Other than that I would make sure you have some valve lash on the compression stroke Jon
This is how it looks like. Nr1 piston is cracked and on nr3 second ring broke in two, maybe it was pinging afterall. Top ring is different than oe, it has no step inside. The medium stones on honing tool were a bit too coarse. Ring gap is 0.6mm on one ring, with 0.4 on rebuild. My old 1.6 rings have 0.5mm with 200.000km on board.
I did a quick dirty repair, changed the pistons with GU engine worn ones, and a set of used oe piston rings from AAM engine. Only put a new head gasket, engine oil and filter. I get piston rattle now and then, initial start got almost 5bar compression, and most annoyingly the ticking/pinging sound is still there. Will do a proper rebore plus oversize pistons and be done with it. Could have fitted a vr6 with same money, but hey, a 1.8 8v is better anyway.
Got the parts for third rebuild. Pistons are 81,5 didnt find bigger. Cost was 1070lei and a cheap 4.2.1 about 550lei. Now i have to remove engine for rebore. The header may need cutting and welding, its for mk4 1.6.
