clicking noise from the engine under load???

[broxby]

Hi everyone , I'm new to the site having only bought my t25 last week! Having great fun so far and have loved reading through the site. there's some cool campers out there!

I hope someone can help me with a problem that started two days ago? After going on a short journey the van started making a clicking noise quite loudly but only when the engine is under load? When you dip the clutch the noise stops. It's definitely coming from the engine bay and sounds like it is going around the wheel and catching on something, but there's no change in engine power or anything.It's a 2.0 Aircooled devon. Please help it's driving me insane!!

[Wolfsburg Willy]

Hi Broxby and welcome. Your clicking noise sounds very much like pre-detonation or 'pinking' caused usually by the ignition timing being too far advanced or a weak mixture. It can also be caused by excessive carbon deposits in the cylinder head/s. I would check the induction system (carb , ducting etc.) for air leaks, check your ignition timing with a strobe light and check the colour of your spark plugs (very light colouring can indicate a weak mixture). If all is OK I would then suspect something deeper like carbon deposits or the wrong octane fuel. Once you have heard an engine pinking you will always identify it, so see if you can find someone who would have a listen whilst you drive.
Oh! and don't ignore it if it is pinking 'cos prolonged use can damage your engine!!

[moggymorgan]

hi broxby, just a thought. Aircooled motors sould run on old style fuel so will need lead replacment additive added when filling up with unleaded fuel. might make a diference to how the engine runs, sure folk on here will know more than me as i am a newbie on Aircooled myself.

[ermie571]

Moggy - who told you that???

May be worth an ask out - I think the feeling is that normal unleaded is fine.....it always was in my Aircooled, the 2.1 watercooled may need super-unleaded depending on the way it is timed.

Em
x

[CovKid]

Pre-detonation has a distinct sound, a bit like chains dragging. If its a rhythmic sound I'd probably that rule out and look elsewhere. As for Aircooled on unleaded, there won;t be many Aircooled engines around now that haven't been subsequently fitted with unleaded heads and you can compensate with timing anyway. The main damage you get from unleaded is to valves/seats.

[broxby]

Thanks for the replies everybody, I've been out this morning and had a good check over but everything with ignition and timing appears to be spot on? The noise is still there as loud as ever and it would now appear that reverse gear has dissapeared!! I've a feeling that the two may be connected?

[CovKid]

Sounds like a job for........SUPER AIDAN!

[ermie571]

Sounds like a job for........SUPER AIDAN!

He would be the gearbox guru!!!

But having just had my run of gear box in, gear box out I can vouch for his knowledge and patience! Had my gearbox tested for nasty noises by jacking up one back wheel and supporting the bus on an axle stand, chocking the front wheels, make sure the wheel is WELL off the ground, and running the bus in all gears. Didn't have to be Einstein to work out the gear box was errrrrr broken!!

get in touch with Aidan - find any of his posts - his number is in his signature. Although he doesn't repair Aircooled boxes (dunno why) he can assist with general diagnosis, and may be able to refer you to someone who can assist further.

Em
x

[kevtherev]

could be a leaking exhaust gasket.. header pipe more likely

[jason k]

. As for Aircooled on unleaded, there won;t be many Aircooled engines around now that haven't been subsequently fitted with unleaded heads and you can compensate with timing anyway. .

the 2000cu Aircooled motor runs on normal unleaded without the need for timing adjustment or additives or anything else.

[CovKid]

I was referring to Aircooled engines in the general sense from beetles onwards. By the 80s, unleaded was no longer an issue.

[Louey]

vw engines were designed to run on unleaded from very early on inthe 70s - I remember having my Bay and every Tom Dick and 'Arry was trying to sell the latest lead replacement gadget to unsuspecting VW owners.

The main issues was how hard the metal used to make the valves was. If you wanted to, you could replace your valves (or the whole cylinder head) so that the valves were made of a more hardened metal. Also, the unleaded fuel combusted at a slightly different moment compared to leaded, so adjusting timing would help this - avoiding pinking.

By the 80's I think all cars were able to run on unleaded without any issues.

As for your issue, I'd have a listen around the whole engine bay and under the van whilst the engine is running - be careful when crawling underneath - Kev's theory of an exhaust gasket or joint sounds likely - even a small hole in the exhaust system

[broxby]

Hey everyone and thanks again for your replies. I've inspected the van further and there's no leaking gaskets anywhere, but would a leaking gasket cause the loss of reverse gear?? Is there anything to do with the linkage for reverse that when loose would click around the gearbox and cause the loss of reverse? I was researching the haynes and have seen there is a reverse cog on a pinion but also a gear selector bracket to help aid the selection of reverse could any of these have worked loose or broken from anybody's previous experience?

[Damien]

Mine stopped going into gears and then wouldn't work at all. Then gave up on the M4. New gearbox time, you could be lucky though.

What i did notice with my old 'box was that the braket (with the rod with the balls on!?! not sure of technical name there!!) held on the selector shaft on gearbox by a single nut was loose, meaning the linkage didn't move far enough to get the gears properly. Check all the CV bolts are done up too, mine were fitted without the washers and had loosened off, could be the knocking sound. Now with the new box, everything as it should be and a oil change all is really quiet.

[broxby]

Hey Everybody, I finally got chance to have a look at it again and the loss of reverse gear was down to the gear linkage! the noise is still there but is now intermittent. At least I can still go on my ollies on the 17th of december!!!!!! Next item on the list is to get the heating sorted.