Hello together, I'm going to introduce myself first: My name is Thomas, I'm 41 years old and I live in Winterthur, Switzerland :-) I work as an elementary teacher but in my free time I also like DIY among other things. I own 3 cars (1988 Camaro, 1993 Alfa Romeo, 2001 Jaguar X-Type). Two of them are out of order. I keep them at my house. I bought the X-Type 3 1/4 years ago when it had around 175000 kilometers, today it has 205'000 km on it. It has shown some problems during the years that I've been driving it but I only really had to replaced the thermostat. Now I had to show the car at the MOT (in Switzerland it's called MFK). I had to replace both sills (inner and outer) becaue of rust which I got done in a body shop (cost me 4000 dollars). I passed MOT today but there is one problem that I'm worrying about. It's an engine noise (at least I think that it's coming from the engine) that has developed already about 1-2 years ago, in the beginning very faint and rarely audible.

I have to go farther back quite a bit in the story and I have to admit things that surely were not good for the engine. First: I used to always go up to 80 km/h in the second gear and then changing to the fifth one. After some time the car started to kind of not putting the gear in correctly when I changed from 2nd to 5th and did terrible noise. Around the same time I suddenly had a clunking noise when moving forth and back very slowly (I heard it when I parked the car and taxied a bit) which I guessed from other threads that it could be the dual mass flywheel problem. Interestingly both problems went away when I started to only go to 50 km/h in the second gear and then use the 3rd gear up to 80. That was about 2 years ago. Then the engine oil light started to show up randomly (especially when driving slowly) for split seconds. At that point I didn't take this too seriously because it came up only very quickly and I didn't know that the light if for the oil pressure, then it came on a bit longer and at some point I checked the engine oil and was shocked. I could fill up about 3-4 litres which means that I had driven for some weeks or even months with a very low oil pressure. I thought that the light was going to warn much earlier and would show the oil level not pressure. Stupidly I only filled up to the minimum then and went on driving without further checking the level. Now I'm writing this because it might or might not be the reason for my engine noise.

About a year ago, I first noticed the engine noise when the engine was warmed-up and I was driving at 60-80km/h holding the speed (pushing the pedal ever so slightly or having cruise control on). At higher speeds I didn't hear anything. Through the year it has gotten worse slowly. But the main thing is, that you the noise goes away when you're off the gas or accelerating moderately (you can hear it though, when accelerating hard). So under no load or a load that is more than just holding the speed, you can't hear it. Also when I got my car back from the body shop the noise wasn't there for some time, so it normally only comes when I have been driving for some kilometres. Sometimes it takes longer, sometimes shorter for the noise to appear, but there isn't really a correlation with engine temperature. So how does the noise sound? That's always difficult to describe. Maybe you know these carinval ratchets that make a clicking sound when you turn them. Or as if you turn a bike's wheel and you hold a piece of thin would to the spokes. So it's like a clicking / ticking / rattling noise getting faster or slower according to the speed. It's not a very low or a very high sound. I have read about engine chain tensioners with some Jaguar models that get bad, so I thought the sound might come from the chain (either being loose or a bad tensioner). When I had my hood open and reved up the engine, I could also hear this sound, so it's not only when driving. I wonder why I can't hear it when I'm moderately accelerating.

What do you think? What would be the best steps to identify the reason for this noise without tearing apart half of the engine? What about the chain (or tensioner)? I have a leaking valve cover gasket... would this be a good opportunity to check and / or replace the chain or tensioner because some parts that had to be removed to get to the chain / tensioner, also have to be removed when replacing the valve cover gasket?

Thanks for any help,
Thomas

 

I can add, that I don't have any stuttering, no engine light coming on, no loss of power. I can also add, that for some time I had a stutter but that was becaue the infamous vaccum hose was ripped. I put some tape around it and the problem has gone. I can as well add that I think the spark plugs haven't been replaced for over 100'000 kilometers , so they will surely be done soon (although in my Camaro they have been working fine for far over 130'000 km). My shop told me that the serpentine belt (not the one with the water pump) should be replaced soon, as it's cracked. Also I have a loud hissing noise from the air conditioning compressor, but only when I put air-conditioning on. Air-conditioning doesn't work reliably when the temperature is high.

 

The best clue might be the fact the noise is occurring under certain drive train loading conditions, that probably eliminates engine timing chains as their loading probably only changes with RPM, not final drive torque.

I assume that your description of previous driving habits would indicate this car has a manual transmission?
The common drive train noise complaints tend to be around half shafts, centre bearings midway down the prop shaft, and with the AWD models...the transfer case.
The ratchet sound you describe would tend to dissuade me from the centre bearing on the prop shaft as that is often described as a whine that can begin at around 35-40mph. Some members report that it can become a vibration that you feel through the drivers seat.

I would perhaps suggest you focus on half shafts and transfer case.
Half shafts with their CV joints will often click when turning a certain direction and and under load....the unmistakable click/ping of a ball bearing being rapidly relieved from a constrained position.
Do some tests and see if you can replicate under load at low speeds with medium to tight turns in either direction.

The transfer case I have no experience with as my X-Type is FWD only, but there are many threads in the forum discussing the transfer case. They are a weakness in the X-Type and prone to failure when subjected to prolonged hard driving.
They also are known for only holding a small amount of lubricant, which often is overlooked in regular maintenance, leading to premature gear and bearing wear and seal failures.

Perhaps you could try to narrow down the location of the noise somehow to see if it is biased towards the front, back, left or right side, centre drive tunnel or centre under dashboard.

Good luck with the hunt and I'm sure other members will chime in with their suggestions to help.

 

Thank you for the help.

Yes, I have a 5-gear manual transmission AWD. Hm, I always felt that the noise was coming from the front, that's why I thought it could be the engine. Also the fact that I had driven with so little engine oil for quite some time. I don't know whether I made this clear: the noise (the rattling / ticking) is permanent when I hold the speed, I mean rhythmical. Maybe I can make a video where you can hear it. And it's audible sometimes also when I have the engine in park and just rev it up. As for turns: the sound doesn't change. But the fact that you pushed me towards a possible drive train problem, made me look for drive train noise on Youtube. And there I heard and remembered (I forgot to mention that before) that some months ago I started hearing a whining / humming noise, especially when driving not very fast and going into turns. It doesn't / didn't occur too often and mostly after having driven for some time. So maybe we're on the right track anyways. I'll be happy to also hear other opinions.

Thanks so far,
Thomas

 

Have you done a full oil change since running the engine on low oil, or just topped it up?
If you haven't done a full oil change, then you might want to do so as you will want to check the old oil and magnetic sump bolt for excessive metal deposits. That will give you an indication whether the low oil situation has allowed significant engine wear to occur.
Pick up a mechanics stethoscope which should help you narrow down the noise source if you can get the engine to produce the rattle when the car is stationary.

 

No, I only topped it up. Would you recommend using 5W30 (that is recommended) when I replace the oil or should I rather use the 5W40 (that I had topped it up with) because it has a rather high oil consumption?

As for identifying the sound, I guess, I'm not really qualified enough to determine, where it could come from. When I sit inside the car, it tends to come from the upper front right side. As I have a little parking problem for the next 2 months (we have some work going on on our street and parking is prohibited then, so the car will be farther away from home), I might wait until June and then completely change the oil and filter and check for metal desposits. I won't be driving a lot until then.