Ford Pinto 2.0 knock

[ThanasisPolitis]

Hello,

I’m experiencing a knocking noise in my Tiger, which seems to be originating from cylinder 3.
I’ve attached a couple of videos that may help in diagnosing the issue.

To provide some context, I recently had the engine tuned on a rolling road (~50 miles ago) and everything was running smoothly with no issues. Since the tune, I haven’t overrevved or raced the engine; I’m using a solid-state rev limiter set at 5400 RPM for safety.

Prior to noticing the knock, I did have an issue with electromagnetic interference (EMI) affecting some sensors, so I replaced the spark plugs from NGK AP7FS (which was used during the tune) to NGK APR6FS. This resolved the EMI issue, and I drove it for about 15 miles before noticing the knocking sound. I then reinstalled the original NGK AP7FS plugs, but the knock persists.

Both engine oil and coolant levels are normal, with no signs of consumption, and there’s no visible smoke from the exhaust.

Any insights into what might be causing this knock would be greatly appreciated!

Best regards,

Thanasis

Edited November 13, 2024 by ThanasisPolitis

[Foz]

Ooh 'eck, that doesn't sound too sweet.  It sounds a bit like a little end knock to me.

First question, what oil are you using ? 

Edited November 13, 2024 by Foz

[Bob Tucker]

Sorry mate,

that sounds like a b***ered big end, especially as iit disappears when you disconnect the plug. 

IMHO its too deep to be a small end. That would be more of a rattle than a clonk.
Hows your oil pressure?

[ThanasisPolitis]

2 hours ago, Foz said:

Ooh 'eck, that doesn't sound too sweet.  It sounds a bit like a little end knock to me.

First question, what oil are you using ? 

I am using Halfords Classic 20w50

[ThanasisPolitis]

16 minutes ago, Bob Tucker said:

Sorry mate,

that sounds like a b***ered big end, especially as iit disappears when you disconnect the plug. 

IMHO its too deep to be a small end. That would be more of a rattle than a clonk.
Hows your oil pressure?

Thank you, I do not have an oil pressure gauge so I do not have that info, however, the oil light extinguishes after engine start and does not come back on while the engine is running.

Edited November 13, 2024 by ThanasisPolitis

[Foz]

I've just had another listen and Bob could well be right. 

Sadly, whatever it is, I think it's going to have to come apart to find out for sure.

 

[ThanasisPolitis]

Thank you very much for your replies!!

I have taken the decision to overhaul the engine over the winter so hopefully Eva will be running again by Spring 2025.

I think now it is time to break the news to my wife and explain how magically the 2025 holiday pot just…disappeared!

[Derek]

Many years ago I had a knock in my pinto which turned out to be a burgered lobe on the cam which was probably caused by the oil spray pipe being blocked. I cannot remember if it disappeared when a plug was disconnected. If you are overhauling the engine perhaps pay attention to the cam etc.

I did have to call the truck of shame to rescue us from the M69. We were on our way to Stoneleigh at the time.

 

[ThanasisPolitis]

Thank you Derek!

I am planning to change everything in the engine, so I can guarantee longevity and reliability.