Odd clicking sound dependent on revs

Sun Apr 05, 2015 10:33 am

My M52 swap is making a very strange ticking sound around 2K rpm - I originally thought it was an interference between the wheel as it only happens at low speed and it comes from the glovebox area, but it's definitely engine related given it relys on revs.

I've had a good poke around (while changing camshaft sensor) and I can't find anything loose or unusual - a bit stuck.

Any ideas?

Sun Apr 05, 2015 9:37 pm

A shot in the dark but.........

Aux belt tensioner ?

and the sound is coming from the glovebox area because the rubber grommet isn't in position properly?

Sun Apr 05, 2015 10:03 pm

I had knocking on that side as the heater matrix as the pipes were connected the wrong way around, it was at higher rpm in my case....

Sun Apr 05, 2015 11:14 pm

JF008 wrote:I had knocking on that side as the heater matrix as the pipes were connected the wrong way around, it was at higher rpm in my case....

A strong possibility. The ticking sound is the diaphragm of the heater valve being forced against its seat by the backwards flow.
Which heater stub on the bulkhead do you have the hose from the back of the cylinder head connected to?

Mon Apr 06, 2015 2:05 pm

It's pretty tight down there and I didn't do the conversion (and the person who did probably wouldn't mess that up) but it looks the the back of the head pipe is connected to the top, and the pipe above the starter is on the bottom. Is that right?

I have been having heater issues when on longer drives the heat will stop, and then come back on randomly.

Mon Apr 06, 2015 2:07 pm

Definitely connected the wrong way around, and the source of your problems.
Name and shame the culprit!

Mon Apr 06, 2015 2:22 pm

Well....you may have solved a long standing source of frustration! Too sunny to spend (another) day greasy, will aim to check out this week. Thank you Sir!!

Cannot...I may never get a ride in his new steed...to be fair I know the finishing touches were a bit of a rush as I needed the car back.

Thu Apr 09, 2015 9:53 pm

YES - thank you. Problem solved. Your assistance is very, very, very highly appreciated.

Thu Apr 09, 2015 10:15 pm

Glad to be of assistance! I hope the valve hasn't been permanently damaged by the reverse flow, and the heater has adequate output.
Any technician worthy of the title, with an understanding of coolant/heater systems should know which way the hoses need to be connected even without previous knowledge, so I suppose it's for the good that the culprit remains anonymous, as I suppose he might be 'angry' if identified.

Thu Apr 09, 2015 10:38 pm

Heater seems to be working great - fingers crossed on the valve also. Wasn't too fiddly to change hoses but really not keen to change the matrix!

Poor fella....