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Engine knock after timing belt snapped
ADJA77 - 30/10/19 at 03:37 PM

Hi, I’m trying to get some advice on a 2.0 pinto which has developed a knock after the timing belt snapped.

Basically it was being driven and then would not start after the car was stopped and then found the timing belt had snapped.
The belt was replaced and seemed fine for a few miles after but then it started to knock.

Sounds possible bottom-end knock.

Is it worth me looking to repair the engine or use replace with another Pinto.

Thanks


ian locostzx9rc2 - 30/10/19 at 03:50 PM

Easy enough to strip it down and have a look


JAG - 30/10/19 at 03:54 PM

Yeah - I'd investigate.

A broken Cam belt doesn't usually cause a bottom end knock. It could still be a problem with a crank bearing but it probably isn't related to the Cam belt failure, most likely just a coincidence.

Is the oil level OK? Is the oil pump working? I'd check those things first.

Do you have an oil pressure gauge on the engine?


ADJA77 - 30/10/19 at 07:11 PM

I’m away at the moment so hope to have a look next week.
I was told that a timing belt snap could cause the piston timing to go out and cause the internals to hit each other.

Was wondering if first thing to check should be to remove sump and looks for any metal bits in the oil


ReMan - 30/10/19 at 07:51 PM

No pinto expert but I think std 2.0 is not interference, so should not bend valves and pistons


rusty nuts - 30/10/19 at 08:10 PM

Recheck the valve and the ignition timing and make sure everything is tightened including the crankshaft pulley bolt .


perksy - 30/10/19 at 08:14 PM

The timing belt turns the distributor drive pulley and the distributor then turns the oil pump by way of a hexagonal drive


Abe - 30/10/19 at 09:48 PM

Gents, am I right in saying that if the OP has a vernier pulley and a hot cam it will become an interference engine? Not sure if you have these OP. I do in my pinto and it was purchased with these mods but haven’t attempted any pulley adjustments yet.


snapper - 31/10/19 at 09:03 AM

Pinto is not an interference engine however a skimmed head and high lift cam could put you in interference territory.
If it was an interference engine now and valve hit piston then a compression test would show 1 or more cylinders with no compression engine would run like a pig.

If it’s not an interference engine then a bottom end knock is unlikely due to engine stopping but if you were at speed and cruised to a stop you may have starved engine of oil.

My bet is that it’s not been timed properly after the new belt fitted.

Cam model/type is stamped on the rear end of the cam, take off rocker cover to see what cam you have.

If you have fitted the belt and used the Ford cam timing marks and not the cam manufacturers settings it could be detonation (pinking) knock.

1.Check compression before starting car again
2. Set cam timing to cam manufacturers settings
3.Set ignition to cam manufacturers recommendations this is most likely above 8 degrees static

Only when you have done these check should you consider pulling the engine.
Replacing big end bearings is relatively simple once engine is out, main bearings require a little more dismantling but again no big deal.

I have rebuilt several Pinto’s and can give you advice on how to put together an oil leak free Pinto if you get that far.

It’s probably something relatively simple that’s causing the knock so do the steps I’ve given you and report back

[Edited on 31/10/19 by snapper]


overdriver - 31/10/19 at 02:32 PM

As a matter of interest does the 'knock' persist throughout the rev range? I've had knocking noises on tick-over caused by a few loose/detached items - mudguard stay, bulkhead panel etc. Even a loose fitting dipstick can generate an alarming sound! I'd also check the alternator bracket mounts - particularly the rear one as this can go 'oval' allowing the alternator to wobble.

Michael.