Running a little hot

[400SE Dave]

Since I got my 400Se it has been running a bit hot. It is consistent and I am not losing water, the fan kicks in etc etc. I have seen a comment about another issue that the temperature sensor may have something to do with this and also the fact it is running very rich. Is that correct/possible??

If yes then I'll change it.......if someone can give me an indication where it is as I haven't got any service bibles yet!!

Look forward to any thoughts.

Cheers, David

[grahamw48]

The gauge may simply be innaccurate (if you're an optimist), since it's not using water.

I'd have thought that a WEAK running engine would generate more heat....and potentially be more damaging, unless it was overfuelling so much that it was washing the bores of oil. In that case probably would refuse to start when hot anyway, stink of petrol and sooty black exhaust and plugs.

Eta: Timing too advanced ? Tight engine after recent re-build ?

Edited by grahamw48 on Monday 29th March 21:40

[400SE Dave]

grahamw48 said:

The gauge may simply be innaccurate (if you're an optimist), since it's not using water.

I'd have thought that a WEAK running engine would generate more heat....and potentially be more damaging, unless it was overfuelling so much that it was washing the bores of oil. In that case probably would refuse to start when hot anyway, stink of petrol and sooty black exhaust and plugs.

Eta: Timing too advanced ? Tight engine after recent re-build ?

Edited by grahamw48 on Monday 29th March 21:40

Does have a Sooty black exhaust, haven't had the plugs out yet, perhaps I'll do that at weekend. Hasn't had a rebuild though. Any other pearls welcome.

Cheers, David

[HOTTY]

Dave
Is the fan coming on whilst driving or after a long run, short run, in traffic after a run or sitting on your drive ?
Is the temp going into the red ? obviously it shouldn't, does the fan kick in before.
I have a 400 and it sits on my drive ages before the fan has to kick in but the 350 seems to warm and need the fan much quicker.
Stephen

[grahamw48]

This 390 seems to come up to temp. really quickly too, but is stable thereafter, and fan working properly.

My 400 on the other hand needed a few miles to display any warmth.

They're all different I guess...bit like women.

[HOTTY]

grahamw48 said:

This 390 seems to come up to temp. really quickly too, but is stable thereafter, and fan working properly.

My 400 on the other hand needed a few miles to display any warmth.

They're all different I guess...bit like women.

All the women I know never seem to get hot and need the heating on 24/7, until i say something wrong then seem to heat up very quickly

[honestjohntoo]

400SE Dave said:

Does have a Sooty black exhaust, haven't had the plugs out yet, perhaps I'll do that at weekend.

Why only 'perhaps'? Its the first thing to do, and be sure to note any difference between each bank of four. You'll find out for sure if the engine running weak and hot, or if it running rich and cooler, with a faulty gauge/temp sensor? As soon as you know, the expertise hereabouts can address the possible causes.

From your reported sooty/black exhaust, its 'odds on' running rich. Forget the temp/gauge problem for now, (with no water loss, probably a red herring) and concentrate on all the reasons why an Efi system overfuels. I'm thinking some of these:

o Coolant temp sensor or its connections and local engine earth faulty.
o Fuel pressure too high due to tired pressure regulator or incorrectly setup adjustable version. 36 psi is usually nominal.
o Blocked air filter.
o Worn throttle pot electrically noisy causing random overfuelling.
o Not sure about Air Flow Meter setup on your engine but its a possibility. Someone knows!

Not exactly your system, but for oodles of reading material on some of the above click here

[400SE Dave]

honestjohntoo said:

400SE Dave said:

Does have a Sooty black exhaust, haven't had the plugs out yet, perhaps I'll do that at weekend.

Why only 'perhaps'?

Time unfortunately, I travel a lot with work so won't be back in Blighty until the weekend! Thanks for the check list though, I'll work through it

HOTTY said:

Dave
Is the fan coming on whilst driving or after a long run, short run, in traffic after a run or sitting on your drive ?
Is the temp going into the red ? obviously it shouldn't, does the fan kick in before.
I have a 400 and it sits on my drive ages before the fan has to kick in but the 350 seems to warm and need the fan much quicker.
Stephen

Fan comes on for sure and normally it kicks in quickly and keeps it below the red. At weekend I was in sustained stop/start traffic and it strayed into the red which worried me a bit but then I got into free traffic and it returned to its' normal position. In general it warms up quite quickly

HOTTY said:

All the women I know never seem to get hot and need the heating on 24/7, until i say something wrong then seem to heat up very quickly

[honestjohntoo]

400SE Dave said:

Time unfortunately, I travel a lot ------ Fan comes on for sure and normally it kicks in quickly and keeps it below the red. At weekend I was in sustained stop/start traffic and it strayed into the red which worried me a bit but then I got into free traffic and it returned to its' normal position. In general it warms up quite quickly

OK, misunderstood, sorry about that ------ from your additional info here, I believe you have two unrelated problems.

1 Rich mixture as indicated by black/sooty exhaust, yet to be confirmed/corrected.

2 Cooling system malfunction as indicated by fast warm-up, unstable temperature reading in slow traffic and normality when cruising. Despite no observed fluid loss, your cooling system is ONLY JUST keeping you out of serious trouble! Suggest urgent review/overhaul to clean out crud.

o Drain the system.
o Forward reverse flush radiator, engine block and heater matrix with garden hose at domestic water pressure.
o Coolant Fill without Airlocks by using/adapting this process to your car. Click Here

[400SE Dave]

[/quote]OK, misunderstood, sorry about that ------ from your additional info here, I believe you have two unrelated problems.

1 Rich mixture as indicated by black/sooty exhaust, yet to be confirmed/corrected.

2 Cooling system malfunction as indicated by fast warm-up, unstable temperature reading in slow traffic and normality when cruising. Despite no observed fluid loss, your cooling system is ONLY JUST keeping you out of serious trouble! Suggest urgent review/overhaul to clean out crud.

o Drain the system.
o Forward reverse flush radiator, engine block and heater matrix with garden hose at domestic water pressure.
o Coolant Fill without Airlocks by using/adapting this process to your car. Click Here
[/quote]



Thanks again, Looks like a weekend in the garage then!! I'll get the plugs out and see what that shows and looks like a cooling system draining at the same time!!

Cheers, David

Edited by 400SE Dave on Wednesday 31st March 09:32

[400SE Dave]

Ok, a bit of an update.

Returned from travels and couldn't resist the diversion into the garage! Got the plugs out and the looked OK on both banks, not too black, in fact looked quite Grey. So due to the low costs involved I changed both the ECU Temp Sensor and the Temp Gauge sender and then went for a spin. I took notice of the warm up time and it took about 4 miles to come to full temp, not sure how that compares to others??? The temp however did sit a little below where it was, outside temps perhaps as it was cold today. When I got back I looked at the exhaust at subjectively speaking I think the exhaust is a little less sooty. Also, the tick over sat bang on 1k revs, it was more like 1200 before.

Left it ticking over on the drive and the temps rose..and rose. Then it clicked, the fan had not cut in!! Checked the fuses, all OK so checked the wire connector on the wires to the fan. Unplugged, blew out any crap and plugged together again. Ignition on, fan came on!!!!!! I guess I missed the golden rule of check the obvious first Not sure if it is a bad earth, a kinked wire or if it was just crap in the connector, I'll try to check all I think. Left it ticking over, fan kicked on and off no problems, temps back to normal.

A couple of quick questions then:-
1. Where does the fan earth to so I can check the connections??
2. More important, I want to put in a manual overide for the fan. How do I do it??

I'm still going to flush the cooling system but will wait until my silicone hoses arrive before doing it.

[HOTTY]

Please you have the over heating sorted.

On my 350 there is a lot of earth cables which look like they are coming from the fuse box contected to one of the two rods that the fan is bolted to. There is also a earth cable from the bolt which holds the rad in place to the chassis.
Dont know if this helps with one of your questions

Stephen

[grahamw48]

HOTTY said:

Please you have the over heating sorted.

On my 350 there is a lot of earth cables which look like they are coming from the fuse box contected to one of the two rods that the fan is bolted to. There is also a earth cable from the bolt which holds the rad in place to the chassis.
Dont know if this helps with one of your questions

Stephen

Sorry...just that you're so right for this thread.

[jmorgan]

Fan override. There are two wires going to the otter switch in the side of the rad. You can check they work by shorting them out. (I have heard that some cars are slightly different though and have a battery to the switch?) On mine they short (mimicking right temp) and the the fan comes on. So, get some piggy back lucar connectors and run two wires to under the dash in a suitable place and fit a make/break switch. The otter is a mare to get at so may need the bonnet off to make it less painful for your knuckles.

I also had a terrible air lock issue with my heater. So I fitted a bleed valve on the top hose as it passes through the bulkhead. T piece of copper plumbing with a boiler bleed thingy (tecnal term that, thingy) came in at around £2.50 and a bit of gas and solder. I used the copper pipe joins on the T with the solder in the ridges to give the pipe something to hold on to.

Then I had the swan neck sealing cap not sealing and that caused issues. Sorted.

Also my header tank was sitting too low for some of the system so raised that as high as I could with the bonnet.

[400SE Dave]

Thanks for info Gents, I'll continue to mess about in the enginbe bay! I am quickly learning that everything is a bar steward to work on, I have the scratches to prove it

grahamw48 said:

Sorry...just that you're so right for this thread.

I guess this is a pop at my technical, or lack of it, knowledge. Trouble is that this is my first trip into TVR ownership and I wouldn't say I am the best DIY mechanic. I'm trying though. That said, if I've misunderstood the comment then ignore the previous sentence

[HOTTY]

400SE Dave said:

Thanks for info Gents, I'll continue to mess about in the enginbe bay! I am quickly learning that everything is a bar steward to work on, I have the scratches to prove it

grahamw48 said:

Sorry...just that you're so right for this thread.

I guess this is a pop at my technical, or lack of it, knowledge. Trouble is that this is my first trip into TVR ownership and I wouldn't say I am the best DIY mechanic. I'm trying though. That said, if I've misunderstood the comment then ignore the previous sentence

No Dave it's no pop at you......Graham is laughing, so I am that my name on Pistonheads is HOTTY
and that we are refering to the water systems getting hot on this thread.
Cheeky bugger, good job he is on holiday or i would fix the 350 and be straight up (well it maybe a couple of months)

Edited by HOTTY on Friday 2nd April 15:21

[400SE Dave]

HOTTY said:

400SE Dave said:

Thanks for info Gents, I'll continue to mess about in the enginbe bay! I am quickly learning that everything is a bar steward to work on, I have the scratches to prove it

grahamw48 said:

Sorry...just that you're so right for this thread.

I guess this is a pop at my technical, or lack of it, knowledge. Trouble is that this is my first trip into TVR ownership and I wouldn't say I am the best DIY mechanic. I'm trying though. That said, if I've misunderstood the comment then ignore the previous sentence

No Dave it's no pop at you......Graham is laughing, so I am that my name on Pistonheads is HOTTY
and that we are refering to the water systems getting hot on this thread.
Cheeky bugger, good job he is on holiday or i would fix the 350 and be straight up (well it maybe a couple of months)

Edited by HOTTY on Friday 2nd April 15:21

Oops, must be getting too senstive these days!! Apologies to Grahamw48 and as I said, if I misunderstood please ignore

Edited by 400SE Dave on Friday 2nd April 15:46

[grahamw48]

Dave, we're all mates on the Wedge forum.