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Oil pressue help needed - please

Hi all,

I'm running a 1300 Fiat X19. It's a lowish milage car, 57K, and shows excellent oil pressure on idle (about 25-30psi) and at 3K rpm (60 psi)

The problem is that when I start it from cold I get a knock for about a second until the oil light goes out. If I then immediatley stopped the engine and started it again - no knock. Also no knock when the engine is restarted when warm.

I understand that it's the same angine as the 128 and other more modern models.

It's as if all the oil is draining out of engine so there is nothing to pump from cold.

I heard that the oil filters need to be the correct type with a non-return valve ? I believe I have a correct aftermarket one installed.

Anybody have any ideas ? could the filter to this ? could incorrect or cheap oil do this ?

thanks

Lee

Reply to
Lee Griffiths
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It may just be one of those things or the beginning of the end. The filter I used to use was a Granada one (fiat 128) this had the non return valve and was larger than standard.

mrcheerful

Reply to
mrcheerful

I can only speak from observational experience - my '88 X1/9 1500 doesn't do this (27k miles - sits for many days / weeks unused).

I doubt choice of oil or filter is the problem. Many old Triumphs use filters that let oil drain back, and if good condition they don't knock on start up.

Oil pump?

Reply to
DocDelete

They hammer like a bag of spanners !

The Triumph has the problem that the filter is mounted on the side of the block, so that it can easily drain out if unvalved. The Fiat OTOH has the filter pointing downwards, so that it doesn't drain out whether it has a valve or not.

I don't have much experience with the 128 SOHC, but I do with the very similar 124 twin cam. They shouldn't be knocking on start up . Sounds like the oil pump is getting a bit tired, possibly by wearing circular recesses in the flat plate that forms the endplate of the pump. You can fix this by running a surface grinder over it, but AFAIR there's a heat treat process if you need to take all that much of it. Details should be in Guy Croft's engine tweak book.

Reply to
Andy Dingley

In my experience, only if the bottom-end is shot (or well on the way). I've had six 2000s, all fitted with original filters various mileages, and

*never* had knocking at start up. I can't speak for anyone else's cars though ;-) Perhaps I've been lucky?
Reply to
DocDelete

My 2000 has done 170,000 miles in 32 years with the original engine and has never had a bottom end overhaul. It still has the original filter arrangement too.

When used every two or three days, it starts without a knock. Once though I left it a fortnight unused in the winter and the first start gave a light knock for a second or two. I put it down to thick oil and enough time for it to seep out of the oilways so that the pump had to displace a lot of air before the oil could get through. Nothing to worry about.

So it doesn't look as though you have been especially lucky, Ken.

Jim

Reply to
Jim Warren

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