Tank Slap - Motorcycle Forum

Long story short: car (2003 Fiesta 1.4) developed a water leak, I fixed water leak (thermostat housing), developed new water leak, replaced water pump (and cambelt while I was there). All back together and the car fired up first time (despite being sat for 3 weeks).

Went for a test drive and the thing felt smooth and silk for its mileage (135,000) and noticeably quicker as we corrected the timing from the previous cambelt change. About 0.5miles from home I lost power and it made a loud tapping noise; clutch in and engine off. Wouldn't turn over.

Tow the car home and take off the cambelt cover expecting the belt to have snapped but it hadn't. Turned the engine over and the auxillary belt moved but the cambelt didn't. Either the teeth have come off the belt or the pulley for some reason isn't turning.

Not a happy bunny !!!

Sounds BAD piston hitting Valves bad :-(

Yep....I'm with Rocket on this one...sounds like the pistons.

But I hope I'm wrong.

Yup.. it was Piston banging Valves - pun intended.

Bent 6 exhaust valves but the pistons are fine, fit for purpose anyway. You can still see the honing marks on the barrel so I'm not fussed about that either

Time to buy some valves and have a go at seating them - yay

What was the cause Cav ?

Hope it's an easy fix.

The crankshaft pulley bolt came loose in the test drive after replacing the timing belt and water pump which caused the cams to stop rotating while the crank was still rotating.

Note to self: even if you torque a bolt up, use loctite!!!

Hopefully it's not an expensive fix.

Bloody lucky you didn't destroy pistons! I'm more than amazed actually.

The pistons just have impression marks thankfully but I will manually turn the crank with the head off to see if there's any odd-looking movement.

Luckily I can get car parts at near cost price but even going off eBay prices I'm looking at £30 for valves and £110 for the head gasket kit. I'll be doing it myself with the help of my girlfriend's dad so I'll be owing him food and drinks as a minimum.

If they have impression marks I'd change them if it were me. Pistons are under emmense forces and those impressions will be stress risers, rather than evenly distributing forces evenly over the piston surface. You may get away with it but being cast alloy I doubt it.

I'm pretty sure it's happened to the car previously as the piston in cylinder 3 (unbent valves) has the deepest impressions yet obviously hasn't come into contact with the valves.

I'm aware the life of the car will likely be shortened however I am strongly considering selling the car shortly after I've fixed it. It's high mileage anyway but that should help in terms of the 'wearability' of heated parts.

For anyone that has me on FB you will have seen that I successfully fixed my car!!

6 bent exhaust valves replaced and lapped into the valve seat. All new gaskets and I spent a good amount of time cleaning the mating faces until they were flawlessly smooth to the touch. Everything back assembled and the moment of truth....

It was slow starting but it had been sat for a couple of weeks and the engine was dry of fuel and oil. After a bit of throttle pumping it fired into life and soon got over the initial jerkiness. Took the car for a test drive and it was smooth and noticeably more powerful now the timing is correct.

Over the moon now and the relief was unreal !!

Well done

Good work!

Good skills