Hi guys and gals. New to the forum and just bought my first rover. It's a 2000 with 150k miles on it. It's got a random peck underneath that almost would make you think it's a rod knock but it comes and goes. Makes no difference cold or hot, loaded or unloaded. I can almost always hear it maybe 1 to 2 pecks when I crank it up and. Can make it do it if I rev it really quick. It sounds like maybe it is just behind the engine around the flywheel area but not certain.

It may do it for a minute or two every 20 minutes. Real random but very noticeable like pecking a hammer against the frame.

 

Purge valve. I don't know if it sounds like a rod knock though.

 

Flex plate bolts to torque converter. Possibility of cracked flex plate.

 

Is that common on these rigs? That is what it sounds like.

 

This is how my truck used to sound, most of us call it "the engine tick". Many of these trucks have some form of engine ticking and the causes could be a long list of possibilities.

I replaced my old thermostat with this one and the engine tick has nearly vanished completely. Most senior members on here will agree that you should change out your thermostat for this one anyways as it will reduce your engine temperatures and potentially pro-long the life of your engine. http://www.roversnorth.com/ProductDe...L500110&type=0

 

Mine is a much lower frequency tick than that and also much lower center, below the truck. It is also random...it will tick maybe 5 times then stop for a bit and so on. Also when it does it you can feel the shake in sync with the noise.

 

You can tell a lot by the frequency. Cam shafts run at half crankshaft frequency. I would have thought that a rod knock would be at 1 or 2 times crankshaft frequency, same for moving liner.

 

Feel the purge valve while the truck is running. You'll feel it. It produces a ticking/tapping noise.

 

by frequency I meant lower in the sound spectrum. Sorry.
Its more of a thud sound instead of a tick if you know what I mean LOL
I would swear it was a piston slap or a rod but its so random. I cant imagine a piston or rod do it at different times and not under either load or no load, hot or cold. This can come and go at any time

 

Nonetheless, the rate of knocking would be useful. At 600 rpm idle, camshaft knock would be 5 times a second. Piston or rod should be 10 or 20.