Club 80-90 Forums

I'm hoping someone can shed light on my problem with my 1990 2.1 Water cooled.
I originally stripped the heads and lapped them - cylinders stuck in head assemblies but managed to prise away but they did lift out partly.
Partly assembled and turned over to test cylinder pressures - coolant was present in engine oil.

Drained the coolant and engine oil.
Fitted new heads and cam followers.
New head gaskets (rubber surround, small green 'o' ring around cylinder and the metal rings in head) with sealant on rubber gasket.
Checked the alignment of the cylinders when replacing the heads - none were sticking up proud.
Sealant around each head nut.
Adjusted tappets - all seated correctly.
Replaced the coolant and engine oil.
Turned the engine with the starter only to check cylinder pressure (count of 10 each cylinder) - all came up 160-165.
This was done without any belts, spark plugs, exhaust system or injectors connected. So no water-pump, alternator running.

I have a lot of coolant present through the pushrod assemblies on both sides - it doesn't appear to be coming from around the headnuts - more from the actual pushrods themselves.
Coolant is in oil

When I put it together I put the coolant in and left the oil drain plug out overnight to see if there was any coolant leakage - but as I have the back end of the van on ramps this was probably a redundant move.
I have researched the oil cooler being the cause but all entries point to oil in the coolant not the other way around.

Am I doing something wrong in testing it this way? 
Should I have everything connected up (belts, water pump etc) and fire it up to see whether it is still leaking?
Can't figure out how it is leaking so much with just turning the engine over.

Starting to feel a bit desperate as I felt I had done everything right and careful when assembling.

Any suggestions are more than welcome.
 

Did you replace the lower black sleeve seals? Lower van and drain out oil and view.

Thanks for the reply Maxstu - I'm assuming you mean the black 'o' ring at the base of the cylinders. 
The answer is 'no' as I'm a bit hesitant in the method used to remove the cylinders. 
My gut tells me that this the possible cause but I want as much input as possible before taking the next step.
The engine is still in situ and I need some input on the best way to remove, clean and replace the cylinders.

I have done further analysis. Heads still on, coolant topped up.  Oil drained yesterday.  Drain plug open and there is a constant drip (one drip every 4-5 seconds) of oil (no coolant visible) for the past 15+ hours.   I suspect the coolant is leaking into the crankcase and somehow making the oil evacuate (remembering the van is still up on the ramps and the drain hole is not at the lowest point.

Cheers

Further to the above (and gleaning as much as I could find from this excellent forum) I am going to remove the cylinder sleeves to clean and replace the lower black 'o' rings. 
There's a high percentage that the leak is on the 3 - 4 cylinder side so I am going to work on that side. 
My suspicions are that cylinder #3 is the culprit is as it can be rotated quite easily. Cylinders #1 and #2 seem much firmer in place so I will let sleeping dogs lie there - if I can.

THE PLAN (would appreciate someone confirming/correcting)
1. Head off. Water-pump removed.
2. Pull Cylinder sleeves off over pistons (they can both be rotated so it looks like they are both loose and shouldn't be a problem).
3. Remove #4 piston gudgeon pin circlip near water pump hole.
4. Pull gudgeon pin using purchased or manufactured* pin puller. (*Can't find any specs on rod and nut size used - help would be appreciated here). Taking care to avoid any side movement of piston using wood.  Avoid damage to interior sleeving.
5. Repeat for piston #3.
6. Clean both lower cylinder surfaces - on sleeves and in housing, using green dishwashing scrubber 'cloth'.
7. Fit new rubber 'o' rings. (*Can someone confirm these are a 'dry' fit - no sealant)
8. Fit piston back into cylinder #3 using ring compressor.  Leaving enough of piston showing to position it back over conrod.
9. Align and refit gudgeon pin (need some input here about method - assume I am pushing against whole assembly suitably packed with wood - using rod and nut.
10. Replace circlip - can't see any entries that show how to do this but assume that this can be done without any special tools other than circlip pliers.
11 Push #3 cylinder sleeve in place.
12. Repeat for 8-11 for #4.
13. Heads and Water-pump back on.

My plan is to test and confirm that the coolant is not present in oil (fingers crossed that I have assumed the correct side).

Thoughts?
 

If you can easily rotate each sleeve, has the engine had a recent rebuild? How about some photos?

By reading through lm assuming you are going to tackle this with the engine in situ? You are a brave chappie! It can be done with appropriate facilities. Yet, without such luxuries though, it's about four hours' work dropping the engine, which would be my preferred choice.

Also, lve seen videos where a mechanic put's
a piston at TDC, lifts the sleeve so the bottom stays just below the oil ring and fits a new lower black seal by walking it down the side of the sleeve on the outside of his fingers to prevent getting it dirty. Obviously the original seal is removed beforehand (they didn't show that part!). No sealant required.

Extracting the piston pin is relatively straightforward. But not always easy. You have the right method. But place clean rags under the piston to catch a wayward flying circlip. And have a telescopic magnet to hand.

About 8-10 inches m8 threaded rod or coachbolt with a wood block spacer and a small washer with slightly smaller diameter than the piston circlip.





If the pin refuses to budge use a bit of gentle heat on piston. Even a hot air gun will do the trick. Dont mix up gudgeon pins with different pistons and clean up the pin entrance on the piston and the circlip hole. Assembly should be simply lubricated and finger push in place.

Pernament mark everything to prevent mixing things up. And make sure the compression rings in the cylinder head are in place. In fact l would probably replace them.

Lastly, before assembly take a look at the head studs and check for corrosion. Take a tap to each head nut and run a die down the head stud thread's and clean off with petrol or alcohol.

Keep asking questions. Here to help to the best of my limited knowledge.

Maxstu - thank you so much for your very detailed reply.  I now have a clearer picture on where I am going.  I have everything disconnected and removed (Exhaust system, engine bay guards, etc) but I am loath to drop the engine as I am not sure of the method (basic facts like where to split it) and I don't have the correct equipment. 
I'm trying to stop things from snowballing any further - this started out as a 'simple' head check and tappet adjustment and resulted in new heads and cam followers and this problem.  
Here is an example of how it is manifesting itself - photo taken after original head lapping and replacement (new heads and same results followed)
I don't believe the engine has had a recent rebuild (at least not in the 2.5 years we have owned it).  250000km on the clock. 
I think to get to the base of cylinder #3 (my suspected cultrit) I'm going to have to remove #4 entirely so I just as well put my mind at rest by removing both.  I will post more photos of progress though. 
Bought a magnet/light on a 'bendy' stick the other day which has proved great for pulling the cam followers out, and getting wayward dropped items.
Starting the cylinder removals on Tuesday -   as it is a public holiday here tomorrow (Australia). Thanks again.[img]file:///S:/TEMP/VW%20Plan%20Printout/IMG20220917165334.jpg[/img]

Any news?

Have done the suspect side (3 and 4) - bit fiddly but managed to get the cylinders out, cleaned up and new 'o' rings fitted. 
The gudgeon pin extraction tool worked a treat (see below)

Had one solitary stud (see below) that I wasn't too happy with (the 'ghost' voices from forums kept nagging me to change it) - supposed to take 2 days to deliver - took 5 days.  It came out without breaking (sigh of relief) after a bit of rattle gun with a stud removal tool.

The original 'o' rings looked a bit ratty and the cylinder 'bed' areas needed cleaning (See photos).  Cleaned carbon deposits from piston and rings.
Was surprised that the gudgeon pins actually did slide in by hand (I had reservations) - bit fussy lining them up but got it in the end

Tomorrow is the 'big test' day - have coolant in the system with no static leaks.

Plan is to put new oil in, turn the engine over with no belts, spark plugs, injectors or rockerbox covers, test the compression on each cylinder (10 turns on each) to see whether the problem is resolved.  This was the point I was at before changing the 'o' rings.  Hoping the gods are kind to me and that the 'o' rings for cylinders 1 and 2 don't need replacing.

BTW the last shot is not rust it's the way the phone caught reflection of the oil deposits ... honest.

Will update again - thanks for following.[img]N:\TEMP\BLUEBIRD\FORUM Photos[/img]

Looking good!

Did you change both sleeve seals and fire combustion rings

I had a complete set of new gaskets for the original job - the top 'o' rings (the green ones) and the metal 'o' gaskets (fire combustion rings?) that fit between the cylinder tops and the heads were basically unused (just installed once and then re-used - no combustion, just one head install, quick engine compression test, and then removal to replace the lower 'o' rings).

You are ready to go.

Good luck!

OK so the initial test went well, and I'm feeling cautiously optimistic. 
Turned the engine over with coolant and oil present (no belts, spark plugs or injectors), 12 times for each cylinder to get pressure readings.
No visible coolant at the rocker area and the compression values have significantly improved from what they were when I started this whole thing (I expected that with the new heads).
Have reconnected the exhaust system and next comes fitting the belts, injectors, plugs etc then will fire her up and let you know how things went.

One area that I would appreciate some input on is the oil cooler. 
I have one very (very) small showing of coolant around where the (new) oil filter meets the cooler.  (It seems that coolant present seems to glow in the dark under a LED light so even the smallest amount is really noticeable).
There doesn't appear to be any coolant leaks from the hoses/area above the cooler but this is the only area I can assume it is coming from.  I'm not up to speed on what is in the oil cooler system itself and it's relationship with the oil system. 
I know that they can break down and oil can appear in the coolant but not vice-versa, or so I understand.
It is the original oil cooler and I have not touched it.
Any thoughts/input would be welcome though.  Cheers

Coolant flows through the chamber to regulate warming and cooling of the oil running through the oil filter. A rubber o ring fits between engine block and chamber for oil retention only.



Ive always found it is the connecting coolant pipes the primary cause of leaks around that area...unless your chamber has been damaged?

It could be simply a bit more tightening of either the screw jubilee clip or a quick tweet of the original spring clips....in the most awkward area of course!

Thanks Maxstu - that helped a lot, now got a better feel for that area.  The image cleared up a lot.