Engine donor dodging, mile munching HDI

[allye]

To clarify towing 1 tonne up hill...

Wide open in 3rd/4th for 2-3mins

[bashbarnard]

Still i would not expect that at all they have VERY efficent engine in regards of creating heat.


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[allye]

It's absolutely fine the rest of the time, unless anyone else can directly compare towing up hills with a remapped car I'll assume it's alright!

[welshpug]

no intercooler?

[allye]

Nope! Just the mild 125bhp map, no cat and no EGR. My guess is the remap causing the slight spike, obviously that coolant system isn't designed for 125bhp.

[Ruan]

I'd replace the thermostat, it makes no difference whether you're towing or not - injected quantity is the same over time. Had HDis on dyno doing testing and monitoring fuel and coolant temperature - with a working thermostat they won't get hot like that and you've got half the airflow on the dyno vs on road. The cooling system in them is designed to keep a stock HDi cool in Dubai all day long whilst holding the engine at full load with lots of reserve capacity. It'd have been pulling off IQ due to the fuel temperature based torque limitation map anyway.

[Matt-Rallye]

As Ruan has said, HDi shouldn't get that warm wether its towing or not! So check your thermostat and make sure the rad isn't blocked up etc

[allye]

Makes no difference whether you are towing or not? I entirely disagree, the car is being put under huge load whilst moving much slower. I can't think of another time I've had it wide open for that period of time. The cooling system also isn't designed for a remapped car, 90 to 125bhp is a big jump with no intercooler.

The thermostat band wagon is null I'd say as it sits in traffic on a hot day no problem. If anything I'd say it's more likely a ageing radiator. No one else have a direct experience towing 1tonne up long hills at 50mph?

[welshpug]

I have had diesels get warm without towing, twatting them up big hills.


Diesel BMW has a weighted gauge with no numbers so I have no idea, and its on a viscous fan.

[Matt-Rallye]

Makes no difference whether you are towing or not? I entirely disagree, the car is being put under huge load whilst moving much slower. I can't think of another time I've had it wide open for that period of time. The cooling system also isn't designed for a remapped car, 90 to 125bhp is a big jump with no intercooler.

The thermostat band wagon is null I'd say as it sits in traffic on a hot day no problem. If anything I'd say it's more likely a ageing radiator. No one else have a direct experience towing 1tonne up long hills at 50mph?

I used to tow way more than 1 tonne cars behind mine that had a stg 1+ map on with no intercooler up huge hills (I live in wales) on a towing dolly. My temp guage NEVER budged above 90 degrees.

Hence my saying check thermostat AND radiator.

[allye]

306 can only tow 1.2tonne!

[Ruan]

Makes no difference whether you are towing or not? I entirely disagree, the car is being put under huge load whilst moving much slower. I can't think of another time I've had it wide open for that period of time. The cooling system also isn't designed for a remapped car, 90 to 125bhp is a big jump with no intercooler.

The thermostat band wagon is null I'd say as it sits in traffic on a hot day no problem. If anything I'd say it's more likely a ageing radiator. No one else have a direct experience towing 1tonne up long hills at 50mph?

FML - "load" makes no difference - the quantity of fuel going in per injection over time is what makes the difference. It's only the fact you can do it for longer when towing.

As said, I've had multiple HDis on dynos with a fraction of the airflow whilst testing coolant temperature, fuel temperature and exhaust temperatures, with intercoolers, without intercoolers under load for prolonged periods of time to test precisely this... Why ask if you're just going to ignore the advice!?

[DeeTurbo]

Could oil quality be another thing that could be an issue?

I remember my dad having an issue when I was young. Tried all sorts, coolant flush, thermostat and then did an oil change and the over heating issue stopped.

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[Matt-Rallye]

306 can only tow 1.2tonne!

It was well before the days i gave a crap about minor technicalities like that i had many other 306's behind it on the dolly weighing over a combined 1.4t probably

This is why i have now got a licence and truck to legally tow 3.5t

[allye]

That all makes sense to be fair, reason I question the thermostat is it sits in hot traffic fine and fans kick in. Perhaps it's only partially opening, that would explain the heating up!

Oil is fresh in their and massively over spec'd for the car.

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306 can only tow 1.2tonne!

It was well before the days i gave a crap about minor technicalities like that i had many other 306's behind it on the dolly weighing over a combined 1.4t probably

This is why i have now got a licence and truck to legally tow 3.5t

Fair play! I wouldn't want to tow much more than 1tonne behind a 306!

[Ruan]

That all makes sense to be fair, reason I question the thermostat is it sits in hot traffic fine and fans kick in. Perhaps it's only partially opening, that would explain the heating up!

The thermostat can often jam at certain points - they just never get hot, so people rarely notice it. It's purely because they produce so little heat unless they are burning a lot of fuel, you can't get the amount of fuel in over time that you can when towing... Which means the thermostat has literally never opened that much in it's whole life, as soon as you hitch up a trailer, have a remap on and floor it up a long hill on a hot day - it's an exceptional case and the thermostat jams and can't open any further.

HDis produce SO little heat on idle, simply the amount flowing through the heater matrix and the hole in the thermostat to allow bleeding is more than enough for the whole engine - hence why you'll never see any problems with it getting hot on idle, they're not like petrols which manage to have the system overheating and boiling over within 5 minutes if they've not got full water flow and forced fan cooling.

[Poodle]

You say the oil is "over-specced", what do you mean exactly? Could be a large part of the issue if you have put in oil that's suitable for the application.

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Sorry, *not suitable.

[Dum-Dum]

I've not towed a tonne in a HDi but I have towed half a tonne up big arse hills with full enthusiasm in both a DW10 and XUD9 and neither temp gauge moved past the mid 80s

[allye]

Finally modified the drivers seat! Bit of weldy weldy, grindy grindy, moving the seat back on the sub frame and removing the tilt has hugely improved driving for 6'6' me. For comparison the passenger seat is all the way back. Just need to sort out a steering wheel on a spacer now.

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And yes I know it's a different seat, better than the one I had and was just spare, will be using waterproof seat covers any way and will keep an eye out for a complete interior, I really like earlier darker pattern of that seat. And also yes the seat behind me is now useless with it all the way back.

[Poodle]

Hmmm... Jealous.

[allye]

Having done a few hundred miles now I can say it's the best thing I've ever done to this car. I'm 6'6' and can now stretch my left leg behind the clutch. Absolute joy!

It dors require a bit of welding and fiddling with the pretensioner, only took me couple hours though so I can fully recommend it. I was looking at RX8 seats but I'm glad I've managed to mantain the OE seats throughout. Desperately need to find a tasteful leather steering wheel that is boss mounted now.

[Magenta Sunset]

when I had my 205, I had a 'boss sleeve' turned on a lathe for me. 6 tapped holes either side for the wheel & boss to screw to, and 3" of spacing away from the boss. could still reach the stalks with fingertips.

[Dum-Dum]

Hmmm... Jealous.

Yeah likewise, very jealous.

[allye]

when I had my 205, I had a 'boss sleeve' turned on a lathe for me. 6 tapped holes either side for the wheel & boss to screw to, and 3" of spacing away from the boss. could still reach the stalks with fingertips.

I've got a spacer ready to go on a boss! Just need a non tacky steering wheel.

[allye]

Really not much to report, I've done 6k in it this summer almost faultlessly, the alternator died again so that was a fun evening in a car park and £200 lighter for a proper 150amp new item, rear wiper stopped working, NS strut making clunking noises, apart from that spot on.

During summer I don't have time to do car work but over the next few months I do, for the 306 this will include a front end refresh, hard to describe but when a cars front end just feels a bit vague and worn, refresh all the wishbone bushes and ball joints. Interior strip, sounds proof and sort the front speakers out, maybe get the injectors refurbed as they are getting noisy and smoke under load.

That's about it! It'll be doing the north coast 500 in November too!