warm up, then knock at idle!

[FP3065TSI]

So this is what going on with my car. I replaced a head gasket today and as i warmed up the car the engine started to sound like a knock noise. Fans are not working at all. im going to try to check if i need a new coolant temp switch to see if thats whats causing my fans not to turn on. What else can cause the car to knock as the car idles for a bit.?

 

[pj91gsx]

what do you mean by knock? like valve ticking, lifter ticking, or spun rod bearing knock noise.

 

[FP3065TSI]

like in between lifter and valve niose

 

[RoasT BeeF]

Did you have any work done to the head? Like new valve seals? Often times the lifters are collapsed and take a good while to pump back up after reassembly.

Your timing could be off also.

 

[pj91gsx]

the lifters are probably making the noise. my friends car had 150,000 miles and the lifters were really bad.

 

[FP3065TSI]

as I checked the noise know its starting to sound like a spun bearing. since when I rev it up it can still be heard. I know it could also be a lifter. I will post a video for further diagnosis.

 

[pj91gsx]

to check for a spun rod bearing, you rev the engine to where you here the knock constantly, then keep pulling out plug wires and when you find the cylinder that the noise stops when you pull the plug wire, that is the cylinder with the spun rod bearing.

 

[FP3065TSI]

Good info i will do that first thing in the morning!

 

[Rob10_99]

Or you could just tear it down before you ruin the crank from the rod beating the hell out of it?

 

[RoasT BeeF]

to check for a spun rod bearing, you rev the engine to where you here the knock constantly, then keep pulling out plug wires and when you find the cylinder that the noise stops when you pull the plug wire, that is the cylinder with the spun rod bearing.

WTF I dont see how this is suppose to work? Removing spark from that cylinder does not stop that piston/rod from moving. The proper way to check for a spun rod bearing is to pull the oil pan.

 

[TxR6guy]

Or just check the Oil Filter.

 

[MilwaukeeGSX]

An exhaust leak coming from the turbo manifold where it meets the head can cause a loud 'ticking' almost like a knock assuming the gasket is ruptured or if you even took it off. If you reused a gasket on its way out then that could be a real possibility.


But I guess if its only at idle and after warm up then probably not.

 

[pj91gsx]

WTF I dont see how this is suppose to work? Removing spark from that cylinder does not stop that piston/rod from moving. The proper way to check for a spun rod bearing is to pull the oil pan.

It works because when you pull out the plug wire there is less stress on the piston so the noise with be much quieter. I have done this method before and it is very easy to do.

 

[BrokenTsi]

Why did you replace a head gasket?

 

[pj91gsx]

WTF I dont see how this is suppose to work? Removing spark from that cylinder does not stop that piston/rod from moving. The proper way to check for a spun rod bearing is to pull the oil pan.

It works because when you pull out the plug wire there is less stress on the piston so the noise with be much quieter. I have done this method before and it is very easy to do. some methods that you think wont work, will work, if you do them right.