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...

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