No Compression

[AustHaflinger]

I had a thread going here http://thehaflinger.com/viewtopic.php?f=11&t=722 about my poor fuel consumption.

I found a guy who knows what he is doing and put the little truck in this morning to get the carby sorted, given an electronic tuneup and a general health check.

The good news is that the carby has the right jets etc and now has the correct mixture etc.

The bad news is that there is no compression on the left hand cylinder but the right is all OK. The Haffie blows smoke when cold but clears in a minute or so when the engine gets a bit of heat into it and when I pulled the spark plugs a week or so ago it was clear that the oil on start was being burnt in the left cylinder only.

The engine was only built two years ago, so thinking optimistically I will first reset the tappets hoping they are not adjusted correctly and are keeping a valve open. If a compression test then shows that there is no improvement I will then do a wet compression test to try an discount rings - optimism is good - but if there is still a valve problem a wet compression test may not be helpful.

So then I guess off with the head to look at valves and the bore etc.

Interestingly on Saturday it would still pull 75kph on the flat so the engine is still developing a bit of power but inview of the low compression I will limit revs to 2500 rpm and no load until the issue is sorted.

Any other views are welcome.

Thanks

Garry

[heinkeljb]

Did you try the compression when hot? More difficult to do when you burn your fingers doing anything, but it might show that the compression increases a bit when hot.

Do you get a puff of smoke when you put your foot down whilst driving - you really need some one following you to see that happen. - valve guides would be worn if it does.

Low compression really should come down to two things - valves and / or rings, but you could also have a bad seal on the head gasket, or a crack in either the barrel / piston / head.

Hope you find it quickly and it's not an expensive fix!

John

[AustHaflinger]

I am quite cranky with the competence of some mechanics. Yesterday he calls me and says that the Haffie has full compression on the right cylinder and absolutely no compression on the left cylinder. When I picked up the Haffie this morning he reiterated that there was no compression on the left cylinder and we discussed possible reasons - hole in piston (discounted), burnt valves, tappets up too much causing a valve to remain open, valve guide causing valve to stick open.

The Haffie was cold and did have a little trouble driving onto the trailer. When I got home I disconnected the spark plug lead to the good cylinder and tried to start up on the bad cylinder and it fired straight away and the engine ran quite well on one cylinder - hang on if there is no compression the engine should not fire and run at all . This dud cylinder had more than enough power to drive off the trailer and into the garage.

So I got my compression tester out and tested the good cylinder first - 115psi which seems about right. I then tested the bad cylinder and got 90psi - a bit too low but a lot better than the mechanic with supposedly 40 years of experience found . I then did a wet test and got 110psi which is getting up to where it should be.

This wet test highlights an issue with the rings, piston or bore but at this stage while an issue, is not a major issue. So the question is, is the oil that is getting burnt on start up (not when running hot) coming into the combustion chamber when the engine is cold seeping past the rings or in through the valve guide.

Given that I have clutch release/spigot bearing noises from the clutch and some other bearing noises coming somewhere indeterminant from the drive train, I am going to leave things as they are for the moment. When I finally find where the bearing noises are coming from (and they are not getting worse with use) and need to fix it I will then pull the left head and barrel and subject to what I find give give it a hone and re-ring, valve grind and redo valve guides etc.

I am really beginning to feel a bit dudded with this Haffie as I was led to believe it was a good usable example and priced accordingly when in fact while it looked good, underneath it was not nearly as good as described. Likewise I am a person who is happy to pay a professional to do good mechanical work bit when someone who came highly recommended cannot even do a simple compression test correctly ....... oh well - not happy.

So work stops on the Haffie and it will be driven locally where reliability will not be an issue until something happens mechanically with it and then I will do all the work as required. I have put other projects on hold to sort this vehicle but there are just too many things to sort so work stops now and the other projects start up again.

I was intending to do an outback trip covering about 3000km with my Landrover club next year - it is for old vehicles and speed is not an issue but reliability is, but with me waiting for things to happen I just cannot take it - looks like the old Landrover FC 101 will have to do it.

Garry

[heinkeljb]

Gary,

Before you start thinking the mechanic has got it all wrong, remember that it is possible to do a compression test one day and get no compression and then the next day get compression - things like a drop of oil from the valves could do it. If the ring gaps had all lined up that could show as low / no compression on a worn cylinder. Then are a brief run, the ring move round a bit and you get some compression back again.

Now it is also possible that his kit has seen better days and therefore not registering correctly. I think in any case you have done the right thing and taken it home. You know now that there is some sort of issue there and that it is a solvable one given some time and money.

Having now been in a couple of Haflingers which were quiet as far as transmission whine / growl I know there is some thing wrong with mine. It will have to wait now for a while as I don't think it is ultra urgent in that something is going to break if I don't fix it now. So similar boat to you - run it for a while and see what it is like. It will also give you time to source things like rings which in your case will be non-standard.

John

[AustHaflinger]

Thanks - yes you are quite right - I will start the process of getting the parts I know I will need and wait until something happens.

Cheers

Garry