Club 80-90 Forums

The Aircooled CU engine on my recently purchased Camper is excessively noisy/clattery & lacks powered

It's been stood for several years & I suspect the hydraulic tappets may be the cause

Wiki and other sources suggest this can sometime be resolved by a 30 mile run. This isn't an option at present as the Van is SORN. Would running the engine for 30-40 minutes achieve the same?

I also want to remove the Tin Ware to examine things more closely, how much of the anciliaries do I need to remove to get the Tin Ware off?

Thanks

Running for a long time can resolve the clatter, but a drive is better at least 30 mins in my experience, what are you wanting to check with the tin off ? It’s reasonably involved to pull it all off

Thanks for the reply.

Going for a drive isn't an option as the van is currently SORN as no MOT or Tax. I need to sort the engine before it can be MOT'd

I want to remove the Tin Ware so I can take a good look at the engine; to check for other causes of it being noisy, to compression test & as a general check. Also I want to give it all a good clean and check over.

I can see its complicated, but I'm in no rush. My main question is what I might need to remove in the way of ancilliaries to get the Tin Ware off, or can it be manipulated off with everything/most things in place. Job no. 1 will be to removed the screws, which I think have been there since it came out of the factory.
 

Presume you have already done an oil and filter change.

Everybody who've done it say that dropping the engine is really easy. I can't confirm, but I do know that many hours can be lost cursing tinware in situe!
Once out the engine can be properly degreased, and crank seals replaced, if not leaking now, they soon will. But to answer your question, carbs(and manifolds) and alternator removed will ease the job. The fan housing will probably need cleaning inside, and the oil cooler given a good blow through.
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Hello,

So another Air-Cooled saga begins...

There is not a lot you can do on the tinware with the engine in place mostly due to the main air turbine and the rear engine mount.

If you remove the air cleaner and throttle linkage : https://www.youtube.com/watch?v=rQp-CP6JJwc
then you will have some access to the top of the crankcase.

If they are still fitted ( ) you can remove the under tins, exposing the push rod tubes, but to do any effective cleaning, you have to be able to remove the deflectors which are behind said tubes. Also, the oil/air cooler will need cleaning.

So that with a big garden tray underneath the engine, a compressor, spraypot and 5 litres of white spirit or gunwash thinners you will get a lot of grime off and see what you have got.

There are 8 bolts, 1 loom, 1 spring and the throttle cable to disconnect to remove the engine.

Here is an older video..https://www.youtube.com/watch?v=JGC3EZXa644
Same method for 1.6 and 2.0 engines

If it starts and runs OK with no smoke or oil leaks, then I would try the 30 mins run technique.
If need be do an oil change with either flushing oil or 10/40 MINERAL oil to loosen things up and flush. Then change the oil again.

Compressions and oil pressure are easy to do and give you firm data.

Finally, if it has been stood for a very long time please sheck the condition of your flexible petrol pipes, there is a filter to change at the outlet of the petrol tank.

Air-Cooled Bliss..

Cordialement,



 

It certainly is an air cooled saga 

The van was an impulse purchase from a neighbor who is moving & it has been sat for several years. There’s lots to do, but it’s a fairly relaxed project, I’m in no rush, & I want to do as much I can myself and enjoy doing it. I’ve got some experience working on cars, but air cooled VW’s are a totally new ball game to me & I’ve never taken on a project like this before.
The video links are especially helpful.
Tinware
I had thought removing this would let me examine the cylinder heads and spark plug holes, but having read the responses here and looking at things more closely I can see that removal of the Tinware is not easy. Added to that the screws in mine are seized in solid.
I’ll have a go at looking inside with a scope for the time being.
I also thought it would be easier to do a compression test with the spark plug holes more accessible, but I can see now that it can be done with the Tinware in place.
I do need to remove the underneath Tinware as it needs repair or replacement. Both sides have some screws that don’t want to budge.
Tappets
I’m fairly convinced these are the cause of both the noise and lack of power.
I have changed the oil (using 20/50 mineral), filter, plugs and air filter. The engine starts okay but remains noisy and was severely lacking in power on the (very cold) morning I drove it round to the MOT Garage. A longer drive is out of the question until it has been MOT’d and it can’t be MOT’d until the engine is running properly – so catch 22.
I took the rocker covers off today and started to get my head round tappet adjustment/preloading. I need to have another look at the manual and videos and return to this. I have the Vans service history for the last 20 years & as far as I can tell the Tappets haven’t been adjusted in that time.
My Plan
From the Responses above it looks like my plan should be:
1. Compression test
2. Engine flush with 10/40 Mineral oil followed by oil and filter change. Is there a specific procedure for the engine flush? I’ve not done one before. Also any particular reason not to use 10/40 or 5/30 synthetic oil for the flush (I already have a supply of this)?
3. Run engine for 30 minutes to try and charge hydraulic tappets
4. Tappet adjustment/preload
Have I got this right & in the right order?
Thanks Again 

Hello

I also thought it would be easier to do a compression test with the spark plug holes more accessible, but I can see now that it can be done with the Tinware in place.

Yup..

and the oil pressure switch is just forward of the distributor.. 24mm IIRC

10to4 wrote: ↑20 Dec 2020, 22:22
I do need to remove the underneath Tinware as it needs repair or replacement. Both sides have some screws that don’t want to budge.

The screw heads are PH3. but when all else fails..use vise grips..and rock the head to and fro a bit..you'll be replacing them anyway

10to4 wrote: ↑20 Dec 2020, 22:22 .
Tappets
I’m fairly convinced these are the cause of both the noise and lack of power.

Do the compression checks.  Run the engine for 30 mins and see if the noise goes away. You will have to get your TDC mark clearly visible
before playing with the static timing and preloads. Watch end of :https://www.youtube.com/watch?v=h4dyMVu_8oc and beginning of :
https://www.youtube.com/watch?v=c4i211jyX38   for details. I would suggest a pre load of 1 1/2 turns.

Oh, and get a couple of spare cork rocker cover gaskets.

10to4 wrote: ↑20 Dec 2020, 22:22

10to4 wrote: ↑20 Dec 2020, 22:22
My Plan
From the Responses above it looks like my plan should be:
1. Compression test
2. Engine flush with 10/40 Mineral oil followed by oil and filter change. Is there a specific procedure for the engine flush? I’ve not done one before. Also any particular reason not to use 10/40 or 5/30 synthetic oil for the flush (I already have a supply of this)?
3. Run engine for 30 minutes to try and charge hydraulic tappets
4. Tappet adjustment/preload
Have I got this right & in the right order?
Thanks Again

That is OK ..
DO NOT USE SYNTHETIC OR SEMI SYNTHETIC OIL IN YOUR AIR-COOLED..
Unless you are into oil leaks.

Air-Cooled Bliss...

Cordialement,


 

Update
Slowly making progress, I think?
I managed to strip the sump plug threads during the Xmas break, delaying things while I waited for a new 16mm plug. That’s now sorted, not too difficult a job if you know someone with the right tools and expertise
I decided to skip the engine flush for now as I felt the risk of ending up with an oil leak too high.
So oil and filter changed then engine run for 35 mins. As far as I can tell I now have 7 out of 8 lifters pumped up, with the lifter for Cyl 4 exhaust valve still soft. All lifters have been adjusted and preloaded, although I struggled with the soft one.
The engine is still a bit clattery, but less so than it was, and seems to be revving more freely. Without Tax & MOT I’m unable to road test it which is a pain.
If I was to remove the soft lifter to manually bleed it, will it come out through the push rod tube, or does the tube have to be removed first?
I’ve also read in several places that setting up the rocker with a small amount of lash can help bleed lifters more quickly, but I can’t get my head round how or why that would work?
The compression test is still pending, hopefully will sort that next week.

10to4 wrote: ↑15 Jan 2021, 17:07 Update
Slowly making progress, I think?
I managed to strip the sump plug threads during the Xmas break, delaying things while I waited for a new 16mm plug. That’s now sorted, not too difficult a job if you know someone with the right tools and expertise
I decided to skip the engine flush for now as I felt the risk of ending up with an oil leak too high.
So oil and filter changed then engine run for 35 mins. As far as I can tell I now have 7 out of 8 lifters pumped up, with the lifter for Cyl 4 exhaust valve still soft. All lifters have been adjusted and preloaded, although I struggled with the soft one.
The engine is still a bit clattery, but less so than it was, and seems to be revving more freely. Without Tax & MOT I’m unable to road test it which is a pain.
If I was to remove the soft lifter to manually bleed it, will it come out through the push rod tube, or does the tube have to be removed first?
I’ve also read in several places that setting up the rocker with a small amount of lash can help bleed lifters more quickly, but I can’t get my head round how or why that would work?
The compression test is still pending, hopefully will sort that next week.

There’s not much to be gained by doing a compression test without all the valves set and a good few hundred mile run to seat everything in. The reading will change , if it runs pretty well no knocks n bangs I would run it and recheck valves oil, water use etc and go from there

You’ve found that most have pumped up, pretty much certain the other will with a drive .

You can pull followers out but you will need to pull out the push rod tube, as they’re on o ring seals you can pull it out and poo it back, be careful for cutting the seals on the cylinder head they are pretty sharp around the edge

The followers take a little patience to get out as build up of residence in the follower aperture in the case , try some break cleaner and some lint free rags to clean it out then work the follower up down until they slide out. I would try squeezing the rocker gear down to push the oil out and run it to see if it pumps up.

The idea of leaving a little extra lash is to allow a little “bounce” and clearance so the valves are definitely fully seated rather than being help open , if the followers aren’t fully pumped up when adjusting it’s possible to over adjust so the valves don’t fully close

Is it ignition? i.e. running on 3 cylinders, that would explain lack of power. Test the HT leads, should be 600 ohms per foot, if ok, then do a spark plug test.