Hi everyone, just joined. Heres the G40 I bought as a non runner:

Has low compression on cylinders one and four, which I was sure was down to an incorrectly fitted head gasket. The cylinder head had been done just before I bought the car. So I got to work replacing it:

G-lader was looking a bit beat up

So gave it a wee spruce up

Removed head

As you can see, lots of action on cylinders two and three, not so much on cylinders one and four.

So I've replaced the head gasket (thought I'd taken a photo of the two of them together, but doesn't seem to have saved. Oh well)

Head back on and camshaft refitted

Mostly rebuilt.

As it turns out, the problem persists.

I'm fairly sure its down to worn piston rings, but I've also been told it could be down to worn or damaged big end bearings. Gonna do another pressure test when my kit arrives to help diagnose.

Currently trying to decide which route to go down.

1. Strip engine again, and replace the piston rings (may not be the fault).

2. Have the full engine remanufactured (sent off to a company who can rebuild it as good as new)

3. Find someone who's selling a PY cylinder block (no joy as yet).

Thanks for reading, sorry its a bit pic heavy.

did you have the head skimmed and pressure tested?

are there any marks on the bores when you turn the engine over by hand?

did you have the head skimmed and pressure tested?

are there any marks on the bores when you turn the engine over by hand?

I can't confirm if the head was skimmed and pressure tested as this work was carried out by the previous owner. The receipt only mentions valve and guide replacement work.

Didn't notice any obvious marks on the bores.

nice ride man, good to see you getting stuck in. welcome.

where did you pick this up from?

nice ride man, good to see you getting stuck in. welcome.

Thanks mate :-D

where did you pick this up from?

Bought it from a fellow dubber (who has a very nice, mega low 6n2), from Bo'ness, who bought it from someone from Creiff. Car was owned by someone in Derby before that.

It's been on here before:

http://www.clubpolo.co.uk/forum/index.php?...c=34973&hl=

Thought that might happen Those wheels are terrible.

Really interesting to read and see whats been done to it previously, I knew it had been well looked after from its current condition. Got some plans of my own once I get the engine problems sorted.

Edited 9 May, 201115 yr by BorisG40

belonged to polo6n1600i and 13kpologt on here!

Did a pressure test:

Before:

Cyl 1: 6 bar

Cyl 2: 13

Cyl 3: 12

Cyl 4: 9

After adding some oil to cyl's 1 and 4:

Cyl 1: 9

Cyl 2: 13

Cyl 3: 12

Cyl 4: 11

Confirms what I suspected in that the cylinder rings are knackered. Luckily, I managed to source a replacement bottom end from cheddarcheese on here. So stripped the engine again today, this time down to the bare block ready for the swapover. Just waiting for the block to arrive which should be on Tues.

Have you still got the knackerd bottom end? Would be willing to take it off your hands if you were thinking of getting rid of it

How did you test if the rings are fried then mate?

interested :-D

Have you still got the knackerd bottom end? Would be willing to take it off your hands if you were thinking of getting rid of it

Yeah, I've still got it, switching them I've next weekend hopefully. Wasn't planning on selling it to be honest, was thinking of re-boring it, fitting bigger pistons and repairing the damage to the bearings. If I do decide to get rid though, you'll have first refusal. :-)

How did you test if the rings are fried then mate?

interested :-D

Rings aren't fried, they're worn and not keeping a proper seal. The oil I added made a temp seal during the test which confirmed they were the problem and not the valves in the head etc..

Ah right, i meant worn and not fried, don't know why i put that.

Just a case off adding a bit of oil down the plug holes?

That's right, just a small amount to create a temporary seal round the piston.

Arrived today.

happy days:-) good luck with the rebuild

How do you get an engine onto a stand without a hoist? Bodge it of course

Finally got there though after using another two sets of ladders and another baton to lift the other side. Left me with this:

Some gunking and a coat of paint later:

So now its ready to be fitted next week if all goes to plan.

Day 1 of the engine swapover:

Out with the old

In with the new

Finishing the rebuild tomorrow and hopefully starting it up.

Edited 29 May, 201115 yr by BorisG40

Well rebuilt the engine today (didn't bother taking any photo's, cos you've seen it already. Anyway, all went to plan, checked the compression with the new bottom end and three cylinders are at 12 bar, one at 11, so that worked out perfect.

However, when I start it up, its as if its only running on three cylinders. Revs ok, but wont hold idle and runs rough. Checked everything, including the timing in case i'd missed a connection or vacuum hose somewhere, but all seems in order. Now I'm thinking I've a dodgy spark plug somewhere or an injector blockage. Thoughts?

Ht leads were running clockwise instead of anti-clockwise. D'oh.

Now idling and revving great, but still has a hesitation and not getting full power. New ht's are on the way and I'll be checking the plugs on Thurs. One step closer though.

vid

I was happy ok, thats why I said G60 instead of G40 ok !!!!

After fitting new spark plugs, the car is now running sweet as a nut. :-D

Anyone want to buy a merc?