Club 80-90 Forums

Hi, please check out the link to the vid of my engine running and making a chiff chiff sound at the 20 second mark onwards.

I've been under the van and listened every where but can't work out where its coming from. Spark plugs are in tight and its not the exhaust, well at least I don't think it is.Any suggestions ?

http://www.youtube.com/watch?v=j9YBwBql ... e=youtu.be" onclick="window.open(this.href);return false;

Is that a missfire?
Does it go if you rev it?

it does go if I rev it. mmmmm, puzzling

sounds like a HT lead breaking down or exhaust manifold gasket blowing, does it change when warms up?

Couple of thoughts;

1. Thats sounds like one heck of a lot of rattling from the valves/lifters - sounds more like a diesel!
2. Is the engine running smoothly or misfiring?
3. If its not a compression leak (spark plugs, exhausts etc) then I would look for a vacuum leak, intake pipes, vacuum pipes to dizzy etc.

What is odd is the random nature, which is why I wondered if it is running smoothly?

MM

As I've said many times, always start with a compression check before embarking on the magical mystery tour of engine diagnosis. It can save a lot of time chasing faults that are just basic ones. £15 buys a reasonable compression guage that can say much about the mechanical state of an engine. If pots check out ok, you can then check electrics and/or fuel. Definately a misfire .

..and there endeth the first commandment.

Hi all, in answer to a few questions....

> It has been having a slight cough on the over run, no major backfiring though.

> I've changed the HT leads and no difference.

> It does rattle and I agree does sound like a diesel and I cannot change the exhaust gaskets as it feels like the studs
will snap before any nuts come undone. Is this rattle within normal limits or is this a really noisy one ?.

I find that a recording of an engine is nothing like the human ear when it comes to normal or excessive noise. It probably isn't backfiring but it has a minor heart murmur (equivalent to when your Granny messes her words up) which makes it inefficient and below par in terms of performance (ask Gran, she knows all about it).

It would be useful to isolate whether the misfire is entirely random or one pot in particular. You could try running the engine with one lead disconnected from each cylinder in turn and see if when one is removed, the chuffing noise goes away. The revs will drop because its running on three but you may find the noise stops on one particular cylinder. Worth a try. Could be a valve that is not seating properly you see or one plug thats not playing ball.

The 'chiff' is a cylinder not igniting every now and then so you need to figure out the above. Is one plug more sooty/oily than the others? That too could help you pinpoint where the trouble is.

Ok Covkid, ill get pulling leads off and see if I can isolate the swine. Cheers for the advice . Ill be back....

As CovKid says, difficult to tell fom a vid, but that engine sounds very noisey to me. I would suspect you've got some valve issues, but as suggested earlier the only way to really tell is with a compression test

MM

yes, when I run it for about an hour it runs quietly but the rest of the time it sounds like a diesel.It does however run really well once it's warmed up etc, no power issues.

When I get 5 I'm going to do a compression test and narrow it down to one cylinder. My problem is that the exhaust nuts cannot be undone as it feels like the studs are going to snap. So, any attempt to get the engine apart is going to mean rebuilds or new engine.

In fact do people bother with rebuilds any more or does everyone just get an exchange unit ?. I've seen 2nd hand engines on ebay for £500 but that just looks like you're buying a pile of some one elses problems.

A few of us do yes. I go right down to the block/crank and work outwards unless the bottom end checks out ok. Usually with these engines its wear in the form of endfloat and knackered heads. Basically the same as a Beetle albeit with additional considerations in the form of corrosion due to insufficient coolant changes. Most don't like them because of the potential for snapped head studs.

Sadly I don't take bookings.

Not many of us who have the balls enough for opening up a wbx...cowards!

Wet plug might indicate one worn valve guide letting oil in and spoiling the spark at low speed, which clears as the load goes on and the plug gets into heat range. Just a thought.