Thursday 30 August 2018

Annoyed!

This is getting annoying now...

After a stupidly expensive 2 week holiday which has not relaxed me and ended badly (long story), I'm still not much closer to resolving my problem.

What is so frustrating is how no-one can pin the problem down - I've spoken to several mechanics, posted videos and pictures to various forums and I've got suggestions that point to every part of the engine! Every time I think I have found something, someone else comes up with another theory.

So, current situation; Simon (ex-GBS) and 1 or 2 others think it's top-end, not bottom end. As it's easier to take the top off, I've done that and checked the valve clearances. All are fine EXCEPT one intake valve on cylinder 3 which is on the limit (0.11mm gap). This is unlikely to be the cause of my rattle as tight valves don't make a noise but I need to fix it anyway, which involves taking the camshafts out to replace a shim. While they are out, I should be able to check the valve springs aren't loose (?), which might cause the rattle and maybe some other stuff (hopefully, Simon can make some suggestions about what to check).

Once done, and assuming I don't find a problem, looks like I will need to go into the bottom end and do/check the big-end bearings. If they aren't the problem, then it's a problem that will need the engine out and engine stripping, not something I have the time, space or tools to do.

This is a real low point in the life of my kit car journey - I've honestly contemplated just sticking the whole thing up for sale and cutting my losses. If I can't fix this, that may be my only option...

One plus is that the DVLA have agreed to give me a new registration, after I sent them a letter explaining how i incorrectly filled in one of the forms and that, actually, all my parts were new (except the gearbox). So i now have a 17 reg plate and i can maybe buy a private plate in future (if i ever get back on the road).

Wednesday 1 August 2018

(Not) Under Pressure

Well, there may be light at the end of the tunnel...although, it's a dreary, grey light...

I popped into my local Ford dealer, he had a listen and said it wasn't the starter motor, as I was hoping. He said it was almost certainly internal - bugger!

After more quality time on YouTube, I found a good series of videos by a US mechanic who had some great suggestions. Basically, for future reference, this is a good diagnostic process to follow to identify an engine noise:

1. Oil pressure test - I should be seeing 3 to 5 bar at idle. If it's low, you might get top-end rattle and, long-term, wear at various points.

2. Compression test - if one or more cylinders have low compression, that indicates a valve (top-end) problem.

3. Spark plug test - remove the HT leads from one cylinder at a time while the engine is running. If the suspect noise disappears, the problem is bottom-end on that cylinder.

So, test 1 (I bought an oil pressure tester) and I am now getting 5 bar at idle BUT I have no idea what I was getting before, as my dash gauge has never worked properly.

Missed out test 2 (I've ordered a compression tester but not arrived yet).

Test 3 - and VOILA!! With the HT lead off cylinder 1, no rattle, no matter how hard I rev. Repeated for the other cylinders and the rattle was still there.

So, I think I've had low oil pressure from day 1 because of that rubbish oil pickup being too close to the bottom of the sump and not allowing the pump to get enough oil round the engine. Over the 3.5k miles I've done in the last year, this lack of oil has caused premature wear in the big-end bearings, to the extent that it is now noticeable on cylinder 1 (and maybe the others to follow soon).

As I've cried wolf a few times recently, I'll hang fire on saying this is definitely the problem until some more people agree with me but it seems plausible.

Now, I just need to work out how to fix it...