Popping sound

[john1]

Are you sure it bows the WD away?

Yip both sides mate def!

I did fear a big problem and it was a wee bit chappy the other day DOH! Tho not now strange.

worst case scenario??

[kevtherev]

IF it is blowing back
and a compression test will see that

then a burnt valve(s) is/are the suspects

At worst... new or used heads, with new valves
My ten pence.. I could be wrong

Has any one adjusted the tappets recently?

[john1]

IF it is blowing back
and a compression test will see that

then a burnt valve(s) is/are the suspects

At worst... new or used heads, with new valves
My ten pence.. I could be wrong

So low compression tells all?

Thanks Kev I will put the rope away.

If thats two new heads with valves, any idea of cost and where to get them? I have never done this job on air cooled T25, can you do it without dropping the lot?

Thanks for your help mate

john

[kevtherev]

That's a step to far ..get it compression tested first

did any one mess with the tappets?

[john1]

That's a step to far ..get it compression tested first

did any one mess with the tappets?

Dont worry kev test will be done this week as soon as I get a chance.

Tappets have not been touched, she was running great 2 weeks ago, then poppig sound when off the gas going down hill.
I did a wee fix with a joint blow on the exhaust at back box to heat exchanger thats why i was thinking i may have disturbed manifold.

Did notice kinda low on oil at the time, just wonder if this has been the killer for top end!!!

Thanks again Kev

john

[kevtherev]

What's the mileage on the engine John?

[sarran1955]

Hello,

Followed thread, still no clue as to what Aircooled engine we're playing with here

Air cooled engines popple ' going down hill in gear'.... ie on overrun,.....where the high and low pressures in a carb setup engine do all sorts of interesting things...... for 2 reasons.

1. You've got a hole in your exhaust.

and/or

2. You've got a burnt out exhaust valve/seat.

Mileage on engine......

DIY regrind,......... do all the valves whilst your'e at it...... cost pence. Plus decent gasket set £ 28.

Its what Aircooled VW is all about..

Cordialement,

[kevtherev]

2L air cooled 1982

john

I assumed it was a CU would you sarran?

[john1]

What's the mileage on the engine John?

Well Kev clock says 51,900. Last 6 MOT's confirm but bus came from south Afirca in 91 so I will leave that thot open.
I have service book and sale history plus newspaper cuttings form the sale over there. it looks ok but I can't be 100% sure.
She looks clean as far as spindles on carbs and general engine appearance doesn't give concern.
Pedal rubbers and interior suggest the same.
As I say not 100%.

Im not sure what life expectancy is for one of these girls.

john

[john1]

Hello,

Followed thread, still no clue as to what Aircooled engine we're playing with here

Air cooled engines popple ' going down hill in gear'.... ie on overrun,.....where the high and low pressures in a carb setup engine do all sorts of interesting things...... for 2 reasons.

1. You've got a hole in your exhaust.

and/or

2. You've got a burnt out exhaust valve/seat.

Mileage on engine......

DIY regrind,......... do all the valves whilst your'e at it...... cost pence. Plus decent gasket set £ 28.

Its what Aircooled VW is all about..

Cordialement,

Hi Sarran

CU engine.
Popple or popping going down hill was new then problems started after.
No hole in exhaust.
Still to test valves.
51,900.
Glad to hear its not going to cost loads of pennies,

Cheers

john

[kevtherev]

52 or152,000 miles is not that bad... if it has been serviced and shows no neglect then you have something worth saving.

[john1]

52 or152,000 miles is not that bad... if it has been serviced and shows no neglect then you have something worth saving.

Def worth saving Kev, just looking for cost if what we think needs done is actually needing done.
Can you change the heads with it all in place? Or do i need to drop the lot out for easy work?

john

[kevtherev]

easy work is better work I say
Don't struggle, if you have to do it, drop the engine, VW made them to be removed easily

[jason k]

dont fanny around, drop it, its much easier

just to clarify the wd40 is being blown away at idle?

your not revving it at all?

[kevtherev]

Ah I wondered when you might pop in Jason