Clunk ? ? ? ? and other things . . . . . .
Discussion
Hi folks,
Just a couple of questions from a new owner!
Sometimes when I start driving off, or have reversed then pulled forward, I hear a clunk from the rear of the car (which I guess is the diff or other part of the final drive) is this a normal thing or should I be worried? I drove another Chimaera before I bought this one and it did the same.
Also Sometimes, around about 2500 or 3000 revs (even when the engine is warm) the car stutters like it cuts out then kicks back in. Doesn't happen very often, but thought I'd ask!!
Please bear with me!! . . . . the heat shielding for the bonnet is coming loose, I bought some spray contact adhesive, is it ok to use this??
Think thats it for now, but lastly, even though it was about 4 degrees C today, I had the top off on the way back from Wales to London, and my God, it was awesome!!! This car is everything and more I expected!!
Thanks in advance, Dan
p.s. Is the poor S reg Chimaera owner who got caught on the westway on the way into London (about 5pm) with his top down in the p**sing down rain on this board?? I feel for you!!
Just a couple of questions from a new owner!
Sometimes when I start driving off, or have reversed then pulled forward, I hear a clunk from the rear of the car (which I guess is the diff or other part of the final drive) is this a normal thing or should I be worried? I drove another Chimaera before I bought this one and it did the same.
Also Sometimes, around about 2500 or 3000 revs (even when the engine is warm) the car stutters like it cuts out then kicks back in. Doesn't happen very often, but thought I'd ask!!
Please bear with me!! . . . . the heat shielding for the bonnet is coming loose, I bought some spray contact adhesive, is it ok to use this??
Think thats it for now, but lastly, even though it was about 4 degrees C today, I had the top off on the way back from Wales to London, and my God, it was awesome!!! This car is everything and more I expected!!
Thanks in advance, Dan
p.s. Is the poor S reg Chimaera owner who got caught on the westway on the way into London (about 5pm) with his top down in the p**sing down rain on this board?? I feel for you!!
Hi, welcome to the fold, and bloody congratulations on getting cold in style.
Re. your questions.
Your clunk sounds like something to do with the drivetrain. Big variety of things ranging from diff mounting bushes to problem with the diff itself, via a selection of suspension related issues. Sensible solution is to get it checked out. Alternative is to simply procrastinate and cure the immediate symptoms by turning up the stereo. Your choice of action should depend on the frequency of the clunk and what you are doing at the time. There is a slim chance that what you are hearing is pressurisation of the fuel tank, but that sounds more like a drum than a clunk.
The rev problem could also be a variety of things, but appears to be a fairly common issue to do with the ECU dealing with signals from the lambda probes. There - I've confused myself (go beyond a carburretor and I'm lost). Type 'lambda' into the search facility and look for a post in the Chimaera section on the 12th Dec. I'd paste the link but I don't know how.
Heat shielding. Spray glue isn't really up to the task. It can't handle the heat. Go and get some Evo stick from your local DIY shop (the stuff that isn't actually on the shelf and you have to ask for). Take the shielding off the bonnet, apply liberally (following instructions) and stick it back on. Works a treat.
Re. your questions.
Your clunk sounds like something to do with the drivetrain. Big variety of things ranging from diff mounting bushes to problem with the diff itself, via a selection of suspension related issues. Sensible solution is to get it checked out. Alternative is to simply procrastinate and cure the immediate symptoms by turning up the stereo. Your choice of action should depend on the frequency of the clunk and what you are doing at the time. There is a slim chance that what you are hearing is pressurisation of the fuel tank, but that sounds more like a drum than a clunk.
The rev problem could also be a variety of things, but appears to be a fairly common issue to do with the ECU dealing with signals from the lambda probes. There - I've confused myself (go beyond a carburretor and I'm lost). Type 'lambda' into the search facility and look for a post in the Chimaera section on the 12th Dec. I'd paste the link but I don't know how.
Heat shielding. Spray glue isn't really up to the task. It can't handle the heat. Go and get some Evo stick from your local DIY shop (the stuff that isn't actually on the shelf and you have to ask for). Take the shielding off the bonnet, apply liberally (following instructions) and stick it back on. Works a treat.
>Sometimes when I start driving off, or have reversed
>then pulled forward, I hear a clunk from the rear of
>the car
Happened to me once
. I 
myself, then remembered I'd just put a heavy briefcase in the boot, which must have become airborne & hit the back panel when I lit up the tyres. Hope yours is something equally terminal. Worn suspension bushes can cause knocking noises, but check your spare wheel & tools are tied down properly first.
>Also Sometimes, around about 2500 or 3000 revs (even
>when the engine is warm) the car stutters like it
>cuts out then kicks back in.
If your car's got a CAT & this mainly happens when the car's been driven for a while it may be related to a common problem. Search for 'fuel cap mod' on TVRCC site
Air has to enter your fuel tank to replace the fuel thats gone out to your engine. 20 years ago fuel tanks were vented to atmosphere & this problem happened more significantly when the breather tube got blocked. The air pressure above the fuel in the tank dropped and fuel delivery stopped when the balance of forces due to pressure & gravity reached the limit for required fuel delivery. The tank's not vented to atmosphere on your car but through a carbon can behind the right headlamp & then to the plenum chamber. You'll soon learn that your cars demand for petrol is greater than Belgiums. When you boot the loud pedal at high engine speeds it's good, but it's costing you! I'm drifting. The air pressure in your tank has dropped and the pump isn't delivering fuel fast enough for a big engine running fast with an open throttle. You can pay to have fuel tank vent system serviced, but the quick fix is to cut a notch in the sealing ring around the fuel filler cap to let air in more quickly. Use search tool to locate the myriad of other posts that discuss the pros/cons of the quick fix. Get Steve Heath's book, it gets a mention in there as do most other things. I'd try the quick fix to see if it really was the problem before forking out for anything else.
Got a cold yet then? I went out last Sunday morning, missus wanted hood off because every other TVR we see seems to have its hood off & she called me a wimp. The ice warning was on before I left my garage. I'm OK, but my missus is now in bed with a head cold
- hence I'm spending my Friday evening doing this rubbish. 
Enjoy yourself.
>then pulled forward, I hear a clunk from the rear of
>the car
Happened to me once
. I myself, then remembered I'd just put a heavy briefcase in the boot, which must have become airborne & hit the back panel when I lit up the tyres. Hope yours is something equally terminal. Worn suspension bushes can cause knocking noises, but check your spare wheel & tools are tied down properly first. >Also Sometimes, around about 2500 or 3000 revs (even
>when the engine is warm) the car stutters like it
>cuts out then kicks back in.
If your car's got a CAT & this mainly happens when the car's been driven for a while it may be related to a common problem. Search for 'fuel cap mod' on TVRCC site
Air has to enter your fuel tank to replace the fuel thats gone out to your engine. 20 years ago fuel tanks were vented to atmosphere & this problem happened more significantly when the breather tube got blocked. The air pressure above the fuel in the tank dropped and fuel delivery stopped when the balance of forces due to pressure & gravity reached the limit for required fuel delivery. The tank's not vented to atmosphere on your car but through a carbon can behind the right headlamp & then to the plenum chamber. You'll soon learn that your cars demand for petrol is greater than Belgiums. When you boot the loud pedal at high engine speeds it's good, but it's costing you! I'm drifting. The air pressure in your tank has dropped and the pump isn't delivering fuel fast enough for a big engine running fast with an open throttle. You can pay to have fuel tank vent system serviced, but the quick fix is to cut a notch in the sealing ring around the fuel filler cap to let air in more quickly. Use search tool to locate the myriad of other posts that discuss the pros/cons of the quick fix. Get Steve Heath's book, it gets a mention in there as do most other things. I'd try the quick fix to see if it really was the problem before forking out for anything else.
Got a cold yet then? I went out last Sunday morning, missus wanted hood off because every other TVR we see seems to have its hood off & she called me a wimp. The ice warning was on before I left my garage. I'm OK, but my missus is now in bed with a head cold
- hence I'm spending my Friday evening doing this rubbish. Enjoy yourself.
Thanks for the replies guys, your all bloody stars!! It's given me something to work from. I'm chuffed that theres a site with such a wealth of knowledge on it!! (pat yourselves on the back!!)
The clunk only seems to happen now and again, and it seems pretty in-offensive, also I think I've heard the fuel tank drumming sound (cheers James and Andrew) you said about, I wondered what that was too!!
As far as the engine stuttering (maybe I made it sound worse that it was), it seems to happen when I have driven the car at low revs for a while, then put my foot down. It passes after a while though (just been out for a longish spin to check this!! - any excuse for a drive!!)
Thanks again guys
Dan
The clunk only seems to happen now and again, and it seems pretty in-offensive, also I think I've heard the fuel tank drumming sound (cheers James and Andrew) you said about, I wondered what that was too!!
As far as the engine stuttering (maybe I made it sound worse that it was), it seems to happen when I have driven the car at low revs for a while, then put my foot down. It passes after a while though (just been out for a longish spin to check this!! - any excuse for a drive!!)
Thanks again guys
Dan
I would not advice the cutting a hole in the seal as this is a safety hazard. I know its been done but there are some issues with this in case of an accident. TVR are required to have anti-roll devices that prevent fuel from leaking out of the tank via the air breather. That requires that the fuel cap is sealed. Notch in seal means that fuel can now escape.
Car tips over onto side or worse, fuel comes out of fuel cap... hot exhaust and bang! Fuel will also tend to spill out when cornering at speed with a full tank, especially on a track day. It ends up in the boot so no one notices until you open it.
Get the purge tank/breather pipe sorted is the safe way to move forward.
This problem is well known on earlier TVRs that used a vent in the fuel cap. The Wedges used a fuel breather but I have had to fit a roll over valve to stop fuel gushing out.
Steve
www.tvrbooks.co.uk
Car tips over onto side or worse, fuel comes out of fuel cap... hot exhaust and bang! Fuel will also tend to spill out when cornering at speed with a full tank, especially on a track day. It ends up in the boot so no one notices until you open it.
Get the purge tank/breather pipe sorted is the safe way to move forward.
This problem is well known on earlier TVRs that used a vent in the fuel cap. The Wedges used a fuel breather but I have had to fit a roll over valve to stop fuel gushing out.
Steve
www.tvrbooks.co.uk
www.pistonheads.com/gassing/topic.asp?t=24037&f=8&h=0&hw=lambda
For the Stuttering around 3000 revs
I posted the topic and I asked when I had the car serviced and they confirmed what PH already knew
>> Edited by the jiffle king on Saturday 11th January 10:14
For the Stuttering around 3000 revs
I posted the topic and I asked when I had the car serviced and they confirmed what PH already knew
>> Edited by the jiffle king on Saturday 11th January 10:14
I've got the clunking sound when just starting to reverse, all the cars i've had with limited slip diffs do that ,so nothing to worry about, i used the fuel cap mod out of steve heaths book it does stop the vacuum building up but doesn't cure the problem because i haven't got a carbon cannister, the last owner spent a fortune trying to cure the cutting out problem with rolling roads , new parts etc but failed, so i read on one post to unplug the computer for about 20mins to reset itself, the cutting out problem has gone completely and hasn't re-occured after 600 miles so far.
manek said: Hmm, it didn't used to clunk when I had it. Nor cut out at 3k rpm! I hope it's nothing serious...
Cheers for the e-mail on the alarm thread Manek, saves me hunting all over!!
I've read a few previous threads, and it seems that a slight clunk is something to be expected on a Limited Slip diff when shifting between reverse and 1st, could even be the cold weather, things shinking and giving a bit of play on the joints and so on, thinking about it, it's only happened a couple of times and each time it's been (literally) freezing outside. Haven't managed to sort a garage yet, so the poor car is very cold at the moment (maybe why you never heard it?!?) Others said they have the same thing happen, and don't seem to worried about it.
Again the same thing with the cutout, cold day again. It's just that both things happened on the same day and worried me a bit, but seem to have passed now so I've stopped worrying!!
Generally the car is perfect though, I'm on another night shift tonight, so I'm gonna go wash it in a while! It needs it!!
>> Edited by dannyboyo on Monday 13th January 00:45
No problem, Danny. Just want to see the car staying well and happy... 
It's been known to do very slightly odd stuff occasionally. I learned -- unless it's obviously serious -- to ignore the odd noise unless it persisted. A lot of them simply went away and didn't come back.
>> Edited by manek on Monday 13th January 10:15
It's been known to do very slightly odd stuff occasionally. I learned -- unless it's obviously serious -- to ignore the odd noise unless it persisted. A lot of them simply went away and didn't come back.
>> Edited by manek on Monday 13th January 10:15
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