what damage can losing your fan belt cause?

[thatch]

Just picked up the Griff from having a new set of head gaskets, however after only 7 miles I noticed the oil pressure drop and orange and red lights come on.

Stopped and looked under the bonnet to see the fan belt dangling free.

refitted, but oid pressure still next to zero.

got towed back to the garage, and within 10 mins of leaving them, they ring to tell me the pressure is now fine again!

Question is why would losing the fan belt cause the oil pressure to drop intermitently? I cant believe it was the pressure sensor misbehaving (coincidence?) - I was convinced the engine had cooked having the water pump disconnected.

any theories?

[Roberto Rica]

First things you should have noticed would be overheating and the alternator/charging light on. If you had gone on then your pressure cap would allow hot coolant to escape and overheating damage would have warped the heads, etc. Sounds like you may have been lucky this time.

Any mayo in the cooling system or under the oil cap?

Rob

[old64er]

An overheated RV8 can make the oil pressure relief valve stick in the pump body, this causes low oil pressure.
If the belt has been thrown then the RV8 will soon overheat.

I had low/nearly no oil pressure from an overheating moment.New pump from ebay and now excellent oil pressure.

The car was fine on the day of the overheating but the next morning when everything had cooled down is when i had the problem.

[spend]

I've had pressure relief spring problems, so stripped & primed a few times. What I have noticed is that it seems to take a while for the sender gauge to comeback, but the oil switch light responds much faster. I think this may be quite normal ~ the sensor is farther away from the pump and may take some time to recover from being 'air-bound' and get 'pumped up' is my hypothesis. Thats why I always rely on the warning light as the critical indicator ~ the gauge is just for interest and has all its own little foibles

Dave

[thatch]

Roberto Rica said:

First things you should have noticed would be overheating and the alternator/charging light on. If you had gone on then your pressure cap would allow hot coolant to escape and overheating damage would have warped the heads, etc. Sounds like you may have been lucky this time.

Any mayo in the cooling system or under the oil cap?

Rob

Thanks Rob,

Because of the work i had just had done - i was watching the temp like a hawk! so I am pretty sure it didnt go too hot. It was the bottom orange light which i saw first, and that prompted me to look at the oil pressure, and then stop.

when it cooled down i looked in the header tank - no mayo - so a good sign!

thanks

[thatch]

old64er said:

An overheated RV8 can make the oil pressure relief valve stick in the pump body, this causes low oil pressure.
If the belt has been thrown then the RV8 will soon overheat.

I had low/nearly no oil pressure from an overheating moment.New pump from ebay and now excellent oil pressure.

The car was fine on the day of the overheating but the next morning when everything had cooled down is when i had the problem.

This makes sense.

The gaskets were replaced because of a clear overheating situation, so i will check with the garage to see if they looked at the pressure relief valve. It could of been damaged previously.


Many thanks

[thatch]

spend said:

I've had pressure relief spring problems, so stripped & primed a few times. What I have noticed is that it seems to take a while for the sender gauge to comeback, but the oil switch light responds much faster. I think this may be quite normal ~ the sensor is farther away from the pump and may take some time to recover from being 'air-bound' and get 'pumped up' is my hypothesis. Thats why I always rely on the warning light as the critical indicator ~ the gauge is just for interest and has all its own little foibles

Dave

Great - will focus on the pressure relief valve and pressure sender unit.

Many thanks all!

[groucho]

They can chafe your neck something awful.

[GreenV8S]

Keep an eye out for HGF over the next few months, the damage doesn't always show up straight away.

[thatch]

GreenV8S said:

Keep an eye out for HGF over the next few months, the damage doesn't always show up straight away.

HGF?

Hairy Green Fairies?

Edited by thatch on Saturday 3rd March 13:35

[pies]

Head gasket failure