During the last week, I have noticed a soft ticking noise coming from what I suspect is the engine bay of my 2003 Discovery 2 with 113,000 miles.

When I turn on the engine from a cold start, I do not hear the sound at idle or when I drive the car, and it is coming up to temp. I only begin to hear the sound once the engine is up to temp and it increases in pace with an increase in RPM. I have read several posts with a similar story to this one. However, this is where it gets strange.

After noticing the sound, I returned home(kept the car running, didn't give the car time to cool off), opened the hood, listened for the sound at idle, didn't hear the noise. I called my buddy over to listen with the hood open. At the same time, I revved the engine(simulating pulling out at an intersection, with the transmission in neutral and my handbrake on), didn't hear the noise. I have tried to diagnose this several times since, and the same thing happens every time.

Today it is raining quite a lot where I live. I drove through a medium-sized puddle, and a large amount of what appeared to be a white gas/vapor appeared behind me, accompanied by a loud noise. I immediately pulled over. I checked my Ultragauge, and my coolant temperature was normal; there were no check engine lights. I also continued to look out of my rearview mirror and didn't see any more of the mysterious white gas/vapor. I drove 6 miles back to my house, still hearing the same ticking noise as before. Once I got home, I performed the same test as before, revving from idle to 3000 RPM in neutral with my handbrake on, didn't hear the noise.

Have any of you encountered a similar phenomenon? I haven't come across this on this forum or others. In light of what happened today, I suspect this has something to do with an exhaust leak somewhere. Still, I'm struggling to understand why I don't hear the noise when I try to diagnose it with a warm engine.

Thanks for any insight you can provide!

P.S. I don't see wild fluctuations in coolant temp on my Ultragauge. The only code I see is P0441(evaporative emission control (EVAP) system faulty) which is a problem I have been trying to solve before I started hearing the noise.

 

mysterious white gas/vapor was the moisture evaporating off your exhaust. Unfortunately that's the only definitive answer I have given the info, that and it appears the sound is movement related which might not signal only an engine issue.

 

@browallace find a quiet parking parking lot roll your window down a driver very very slowly and listen, could be the drive shaft. Note this is not a leave until later thing you need to get it replaced if it is.

 

whowa004 Thanks for seconding my theory on the exhaust, I'm planning to go out and examine the exhaust from the manifold back once the rain stops.

Richard Gallant Thanks for raising the driveshaft issue. It makes sense this could be the problem and I have heard a front drive shaft failure is catastrophic. The front driveshaft on mine was replaced by the previous owner roughly 5k miles ago with the regreasable kit from lucky8 and it was regreased roughly 3k miles ago. I put a 2 inch lift in roughly 500 miles ago and it appears I should have upgraded my driveshaft at the same time based on the product description he installed.

 

Quick followup, just tried driving slow in a quiet place after letting my car sit for 4-5 hours. Didn't hear the noise. I'd still like to confirm it is not the driveshaft. Are there any tell tale signs indicating driveshaft wear or damage? I'm new to the Land Rover game and will take any help I can get.

 

I had a L8 driveshaft fail in under 10K miles...bought it due to not knowing plans of the disco then proceeded to lift it, it did not last long. Also that shaft does not come greased so it's possible it didn't get greased upon initial installation and is already roasted. I have tom woods shafts in both my d2s and have had zero complaints. Unfortunately the odds are the transfer case in the 03 does not have CDL capabilities. Easy enough to confirm, quick good for an image of the location (easier than trying to describe), if by some chance it's there you can lock the CDL and pull the front shaft to help diagnose aside from just puling the shaft and checking for play.

 

I'll take a pic/video in a bit. I think my exhaust could be running hot(evident from the steam incident yesterday) and maybe cooked the driveshaft. If this is the issue I'd probably go with the Tom Woods replacement or the Atlantic British one. I'd also need to sort out the hot exhaust too, or else the problem will repeat itself. I'm putting in an inline thermostat this week so hopefully my engine will run a bit cooler, not sure how this will affect exhaust temp though.

 

It's the cats right there that toast the shaft... If yours are clogged they will heat.

 

Exhaust will steam every time it gets that wet/submerged... Not a characteristic that is something to worry about. The exhaust location (specifically the pass side cat) toasts shafts if they are not greased regularly.

 

Dave03S thanks for the input, any tips on how to tell if the cats are clogged other than the fact they are getting hot?

Also if I was having an issue with the cats would my check engine light/code come on?