Impressions from first long trip
Discussion
We drove roughly 600 miles over the weekend to attend the Euro Auto Festival in South Carolina, which included some amazing roads through the Appalachian mountains in Western North Carolina. The car performed perfectly, as those in the know would expect, but I did have a few questions for the more experienced owners among us...
With the windows down and roof on it got a bit whiffy with exhaust fumes, but I do have a small leak at the manifold so that might be the culprit? It was more than I would expect from a small leak though. Is this normal?
The coolant temp struggled to reach 70 with the cooler air, but does fine in traffic bouncing off the 90 mark with the help of the fans. I wondering if that is a stuck thermostat? Easy enough but wanted to make sure I’m barking up the right tree because I think there are some opinions on the location of the temp sender?
The loudest noise (apart from the odometer) is wind noise that seems to come from the top of the windscreen. Is there anything that can be done to remedy that? Not a big deal but I was pleasantly surprised how quiet the cabin is cruising at 80mph.
I stopped for petrol a lot, not sure how many times, or what kind of mpg I’m getting because it doesn’t matter a whole lot. I didn’t want to top off just in case I discovered a leaky cap or something more sinister on a long run so just put in 6 or 7 small US gallons at a time. Do you guys fill all the way? Am I worrying over nothing?
I appreciate any feedback!
Here we are in some great company (the Traveller had a Toyota lump and modern brakes, etc. and the DeLorean was like new!
With the windows down and roof on it got a bit whiffy with exhaust fumes, but I do have a small leak at the manifold so that might be the culprit? It was more than I would expect from a small leak though. Is this normal?
The coolant temp struggled to reach 70 with the cooler air, but does fine in traffic bouncing off the 90 mark with the help of the fans. I wondering if that is a stuck thermostat? Easy enough but wanted to make sure I’m barking up the right tree because I think there are some opinions on the location of the temp sender?
The loudest noise (apart from the odometer) is wind noise that seems to come from the top of the windscreen. Is there anything that can be done to remedy that? Not a big deal but I was pleasantly surprised how quiet the cabin is cruising at 80mph.
I stopped for petrol a lot, not sure how many times, or what kind of mpg I’m getting because it doesn’t matter a whole lot. I didn’t want to top off just in case I discovered a leaky cap or something more sinister on a long run so just put in 6 or 7 small US gallons at a time. Do you guys fill all the way? Am I worrying over nothing?
I appreciate any feedback!
Here we are in some great company (the Traveller had a Toyota lump and modern brakes, etc. and the DeLorean was like new!
If your car is pre Catted there’s a good chance in slow traffic you will smell some fumes, made worse by an exhaust leak as there’s a good chance it can come back and into the car through various places that are not perfectly sealed. It is actually a good idea to do some mpg checks just to assess how efficient everything runs.
You shouldn’t get wind noise through the roof lines, maybe the windscreen seal has worn and not completely sealing against the roof panel.
On the whole your temp readings sound normal. On the move and in cooler air they do tend to run a bit cooler than perfect when on the move. The fact the fans kick in and out in traffic is another good sign although yes you can get a sticky thermostat especially if the car has stood for any length of time but yours sounds fairly normal to me. If you are using standard 7 grade spark plugs it’s worth looking into using a 6 grade as I believe that helps burn off unused fuel better and defo promotes less sooty plugs when you check them. This might help with fumes.
You shouldn’t get wind noise through the roof lines, maybe the windscreen seal has worn and not completely sealing against the roof panel.
On the whole your temp readings sound normal. On the move and in cooler air they do tend to run a bit cooler than perfect when on the move. The fact the fans kick in and out in traffic is another good sign although yes you can get a sticky thermostat especially if the car has stood for any length of time but yours sounds fairly normal to me. If you are using standard 7 grade spark plugs it’s worth looking into using a 6 grade as I believe that helps burn off unused fuel better and defo promotes less sooty plugs when you check them. This might help with fumes.
They do around 23-28 mpg, (UK Gs), so expect to put 6 US gallons (5 UK gallons) in 5 times on that length of trip.
They take 54 litres to fill, so about 12 UK gallons, or 14.4 US gallons. I have never heard of a problem from a virtually full tank, though do avoid absolutely brimming it to the last drop.
They take 54 litres to fill, so about 12 UK gallons, or 14.4 US gallons. I have never heard of a problem from a virtually full tank, though do avoid absolutely brimming it to the last drop.
Thanks for the feedback gents.
It’s obvious now but didn’t dean on me until mentioned that the fumes I am smelling are pre-cat fumes. I do have all cats in place still so this must be my manifold leak coming in via the cabin air intakes. It’s not a job I’m looking forward to but is a little more urgent now that it’s getting colder and the roof will be in more.
I think I’m about right on the mpg but I will do a couple of full tanks now to see what it really is. My tyres are a tad smaller than original now so I’ll need to find a way to measure the miles - I heard there’s an app for that!
The wind noise might be from the wipers? It certainly seems to come from the top of the windscreen though so I will check the rubber trim just in case it’s lifting when moving along.
I’ll check the plugs, perhaps replace if they are the cooler temp. Most of the year the challenge here is high temps, which it copes very well in. Better than I did to be honest - would love just some air conditioning!! I’ll hold off on the thermostat until I’m in there playing with something else coolant related. It sounds like it is probably fine anyway.
Oh, the best part of driving in the mountains on the interstate was to just blast from 75 to 90 up steep hills leaving all of the people that had been previously annoying me in my dust!
It’s obvious now but didn’t dean on me until mentioned that the fumes I am smelling are pre-cat fumes. I do have all cats in place still so this must be my manifold leak coming in via the cabin air intakes. It’s not a job I’m looking forward to but is a little more urgent now that it’s getting colder and the roof will be in more.
I think I’m about right on the mpg but I will do a couple of full tanks now to see what it really is. My tyres are a tad smaller than original now so I’ll need to find a way to measure the miles - I heard there’s an app for that!
The wind noise might be from the wipers? It certainly seems to come from the top of the windscreen though so I will check the rubber trim just in case it’s lifting when moving along.
I’ll check the plugs, perhaps replace if they are the cooler temp. Most of the year the challenge here is high temps, which it copes very well in. Better than I did to be honest - would love just some air conditioning!! I’ll hold off on the thermostat until I’m in there playing with something else coolant related. It sounds like it is probably fine anyway.
Oh, the best part of driving in the mountains on the interstate was to just blast from 75 to 90 up steep hills leaving all of the people that had been previously annoying me in my dust!
Your last comment made me smile - we have a lot of horsepower per ton, and it shows at times like that.
The wind noise on mine comes from where the tops of the windows meet the roof each side - air leaks in. Also the mirrors do make a fair bit of wind noise, it's the narrow gap between mirror and door frame that causes it.
Make sure your targa panel is fitted tight, ie it takes a bit of shove to click the alloy folding bars into place in the rear section. If it is too loose you can lose the panel at speed. Last time mine did that, it was on a track day at 115 mph, when it went about 30 feet up in the air and fortunately landed on the grass at the side of the track (saw the video in race control after). Guy behind needed fresh undercrackers. The reason it flies out is aerodynamics. If you remember your school physics lesson on what makes planes fly, you can work out what makes targa panels fly - it's the same thing.
The wind noise on mine comes from where the tops of the windows meet the roof each side - air leaks in. Also the mirrors do make a fair bit of wind noise, it's the narrow gap between mirror and door frame that causes it.
Make sure your targa panel is fitted tight, ie it takes a bit of shove to click the alloy folding bars into place in the rear section. If it is too loose you can lose the panel at speed. Last time mine did that, it was on a track day at 115 mph, when it went about 30 feet up in the air and fortunately landed on the grass at the side of the track (saw the video in race control after). Guy behind needed fresh undercrackers. The reason it flies out is aerodynamics. If you remember your school physics lesson on what makes planes fly, you can work out what makes targa panels fly - it's the same thing.
Loach1 said:
The coolant temp struggled to reach 70 with the cooler air, but does fine in traffic bouncing off the 90 mark with the help of the fans. I wondering if that is a stuck thermostat? ]
I had the same problem on my car, turned out that a 74ºc thermostat had been fitted. An 82ºc cured the problem and it now runs between 82 and 92 (when the fans come on). Contrary to what some may say TVRs don't overheat unless there is some fault in the cooling system. By-the-way, make sure you buy the correct thermostat as the TVR ones have a small hole in the mounting plate to act as a by-pass.
Good luck, enjoy your car.
Hedgehopper said:
I had the same problem on my car, turned out that a 74ºc thermostat had been fitted. An 82ºc cured the problem and it now runs between 82 and 92 (when the fans come on). Contrary to what some may say TVRs don't overheat unless there is some fault in the cooling system.
By-the-way, make sure you buy the correct thermostat as the TVR ones have a small hole in the mounting plate to act as a by-pass.
Good luck, enjoy your car.
The TVR official part has a larger opening orifice than a standard thermostat.By-the-way, make sure you buy the correct thermostat as the TVR ones have a small hole in the mounting plate to act as a by-pass.
Good luck, enjoy your car.
^^^^^^^^^^^^^^^^^^
There are two 82ºc thermostats, this is the high-flow one...…….
https://tvr-parts.com/tvr-parts/part-details/tvr-e...
There are two 82ºc thermostats, this is the high-flow one...…….
https://tvr-parts.com/tvr-parts/part-details/tvr-e...
I did have a problem in winter driving ( use my car all year round except when ice and salt are about) with very low water temp, it was fine when in slow traffic.
The temp gauge would drop below 70 with the cold blast through the rad making the cabin heater not get up to temp and the fuel consumption would fall due to enrichment kicking in.
During the winter months I fit a partial blanking panel in the middle of the rad which allows for a hotter water temp while on the move.
The temp gauge would drop below 70 with the cold blast through the rad making the cabin heater not get up to temp and the fuel consumption would fall due to enrichment kicking in.
During the winter months I fit a partial blanking panel in the middle of the rad which allows for a hotter water temp while on the move.
Oddly and I don’t really know why mine has always had a warm Heater even in winter time.
If I was to start from cold and hit a motorway within a few minutes, it won’t get particularly hot but if I’ve got it somewhere near upto temp first it stays hot.
I’ve had the temp gauge go as low as 60d but still maintained a warm heater. It’s never ran cold air alone put it that way.
I’ve often read about cold heaters and considered myself very lucky as Ive used mine all year round for a number of years now.
If I was to start from cold and hit a motorway within a few minutes, it won’t get particularly hot but if I’ve got it somewhere near upto temp first it stays hot.
I’ve had the temp gauge go as low as 60d but still maintained a warm heater. It’s never ran cold air alone put it that way.
I’ve often read about cold heaters and considered myself very lucky as Ive used mine all year round for a number of years now.
QBee said:
They do around 23-28 mpg, (UK Gs),
I wish! since new my '99 450 averages 18-22 mpg (14-18 US mpg). 600 miles would be just under three full tanks for me. One important tip is to learn your fuel gauge - fill up when 1/4 and 1/8 and remember how much you're putting in. It turns out that mine is pretty accurate at the empty end, but my friend ran out of fuel when it was indicating just under 1/8.
Hedgehopper said:
Loach1 said:
The coolant temp struggled to reach 70 with the cooler air, but does fine in traffic bouncing off the 90 mark with the help of the fans. I wondering if that is a stuck thermostat? ]
I had the same problem on my car, turned out that a 74ºc thermostat had been fitted. An 82ºc cured the problem and it now runs between 82 and 92 (when the fans come on). Contrary to what some may say TVRs don't overheat unless there is some fault in the cooling system. By-the-way, make sure you buy the correct thermostat as the TVR ones have a small hole in the mounting plate to act as a by-pass.
Good luck, enjoy your car.
It's a constant source of amusement to me some people are still trying to solve over heating issues with a lower value thermostat
I've run an 88 degree thermostat for years now, I do so because that's what's fitted to a Range Rover, a vehicle that runs the same engine. Contrary to popular myth a Chimaera with a healthy cooling system is not at all prone to overheating, quite the opposite in fact, at speed on a cold day its quite common to see true coolant temps in the low 80's.
Also be aware the TVR temp gauge is not at all accurate, the key issue being where TVR fitted the sender, a good improvement in gauge accuracy is to remove the wire from the TVR positioned sensor and reconnect it to the Range Rover sender TVR just left in place, to get the gauge matched to this sender all that's required is a resistor as described in the post below.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
The Rover V8 engine is designed to run at or close to 90 degrees so a thermostat that is fully open at 88 degrees is ideal, the Chimaera cooling system is actually over specified and the aluminum engine block is also super efficient at losing heat when you're driving at speed on a cold day as all that cool air does a very effective job of taking heat away in the same way as an air cooled engine functions.
This inherent over cooling issue is merely exasperated if a thermostat of a lower value than 88 degrees is fitted, people who fit low value thermostats simply don't understand how a thermostat is designed to work! Fit a 74 degree thermostat and the engine will sill reach fan activation temp at 93 degrees when idling in traffic so it isn't going to help one bit with overheating issues, over heating issues should be corrected properly by correcting coolant leaks, replacing a failed water pump or most likely by reconditioning the radiator which become increasingly inefficient as they age and internally corrode/silt up.
All that happens if you fit a 74 degree thermostat is the engine will take longer to warm up which is bad for fuel consumption and accelerates engine wear, a 74 degree thermostat will not make the coolant system more efficient because that's governed by the coolant capacity, radiator size and fan operation.... not the thermostat value
The OP is complaining about exhaust gasses entering the cabin, this can be made worse with a low value thermostat as the engine management system enriches the air fuel ratio on a cold engine so it could be the engine is running excessively rich, on a run between 70-80 mph the car should be delivering 27mpg (UK) and average 22mpg overall, anything less demands further investigation.
I recommend taking the car to a local garage with a proper 5 gas analyser that will give you a reliable reading on:
1. Carbon Monoxide (CO)
2. Carbon Dioxide (CO2)
3. Fuel Dependent Hydro Carbons (HC)
4. Oxygen (O2/Lambda)
5. Nitric Oxide (NOx)
Pay special attention to the fuel dependent hydro carbons (HC) and oxygen (O2), these are the UK max allowable values for a car with cats:
Natural idle test (450-1500rpm)
CO 0.300 %VOL Max
Fast idle test (2500-3000rpm)
CO 0.200 % Vol Max
HC 200 ppm vol Max
Lambda 0.970 (MIN) 1.030 (Max)
These are the MAX figures and anything richer is well out, often what you see on a well tuned healthy Chimaera fitted with catalytic converts will be way better than the above, indeed you should be shooting for are these figures:
Natural idle (450-1500rpm)
CO 0.00 %VOL
Fast idle (2500-3000rpm)
CO 0.00 % Vol
HC 5 ppm
Lambda 1.00 (14.7:1 AFR)
Finally if you wanted check your AFRs on the move it's well worth fitting a wide band lambda sensor and gauge which are inexpensive these days and provide an invaluable window on combustion, alternatively just go old skool and remove a spark plug or two and read by colour which is quick down and dirty way to get an indication on whether your engine is running rich. TVR fitted No7 plugs which are way to cold so your first step should be to fit a set of NGK BPR6ES or better still the newer iridium variant and go from there.
After that look at ditching the dreadful and failure prone spark plug extenders used by TVR which often promote misfires and so will give a poor running engine that also delivers very high emissions and poor fuel economy, just be sure to protect the plug ends of your HT leads (plug wires) and you'll never look back
Read my post here where I cover my double wrapped method which is a completely bullet proof solution to deleting the dreadful plug extenders:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Edited by ChimpOnGas on Thursday 1st November 08:40
I have ordered a new thermostat from TVR parts, 82 deg opening with the higher flow (E2027HF). That may help but it’s not 88 deg...
I ditched the plug extenders almost immediately using socks and it sorted out all of my minor running issues. So far so good with no sign of scorching. Using the numerous guides on the engine I don’t expect problems because nothing is touching the manifolds.
I have a wide band but haven’t tried it yet. I’d like to get bungs welded into the manifolds so I can check each bank, which I can do more easily when I address the manifold to head leak.
My friendly local garage has an exhaust analyzer, so I’ll see if they can check out my numbers and report back.
Thanks for the advice!
I ditched the plug extenders almost immediately using socks and it sorted out all of my minor running issues. So far so good with no sign of scorching. Using the numerous guides on the engine I don’t expect problems because nothing is touching the manifolds.
I have a wide band but haven’t tried it yet. I’d like to get bungs welded into the manifolds so I can check each bank, which I can do more easily when I address the manifold to head leak.
My friendly local garage has an exhaust analyzer, so I’ll see if they can check out my numbers and report back.
Thanks for the advice!
Great stuff 
You may also consider experimenting with switching your vacuum advance unit from the emissions based ported vacuum strategy to a traditional old skool full manifold vacuum signal, this will safely give you 5-7 degrees more ignition advance at idle which should deliver a smoother idle at the excessively lean 14.7:1 AFR the Lucas 14CUX ECU forces the engine to run at.
Leaner mixtures have a slower flame front so lighting the fire earlier will give other benefits too like cooler exhaust manifold temps, initial tip in and throttle response will also be enhanced.
Clearly that extra ignition timing will raise your idle speed so to correct this simply wind in the base idle screw on the throttle body to give a nice steady 1,000rpm. Be aware running an advanced idle timing strategy will increase the nitrogen oxides your engine emits into the atmosphere (NOx) but that's the only downside, in all other respects idling at 18 degrees works way better than the 10-12 degrees that was only used to reduce emissions.
The above timing change should only be made using the vacuum advance unit as you only want that extra advance at idle (high manifold vacuum condition), don't be tempted to just adjust the distributor to achieve an 18 degrees idle or you'll be at 36 degrees all out at 3,000rpm and under load this puts you dangerously close or in the engine damaging detonation zone.
Enjoy
You may also consider experimenting with switching your vacuum advance unit from the emissions based ported vacuum strategy to a traditional old skool full manifold vacuum signal, this will safely give you 5-7 degrees more ignition advance at idle which should deliver a smoother idle at the excessively lean 14.7:1 AFR the Lucas 14CUX ECU forces the engine to run at.
Leaner mixtures have a slower flame front so lighting the fire earlier will give other benefits too like cooler exhaust manifold temps, initial tip in and throttle response will also be enhanced.
Clearly that extra ignition timing will raise your idle speed so to correct this simply wind in the base idle screw on the throttle body to give a nice steady 1,000rpm. Be aware running an advanced idle timing strategy will increase the nitrogen oxides your engine emits into the atmosphere (NOx) but that's the only downside, in all other respects idling at 18 degrees works way better than the 10-12 degrees that was only used to reduce emissions.
The above timing change should only be made using the vacuum advance unit as you only want that extra advance at idle (high manifold vacuum condition), don't be tempted to just adjust the distributor to achieve an 18 degrees idle or you'll be at 36 degrees all out at 3,000rpm and under load this puts you dangerously close or in the engine damaging detonation zone.
Enjoy
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