Thread: How mount thicker intercooler?

Hey Arthur, are all your temperature observations from a coolant temp gauge or one of those fancy gauges that has a sensor bolted to the head?

Whilst we are on the topic of intercoolers... Does anyone know the purpose of the rubber wrapping on the metal turbo pipe from the turbo to the bottom of the intercooler (the pipe between the elbow and the straight coupling)? Is it purely insulation? Wouldn't the rubber just soak up the heat from the close proximity exhaust anyway?

Originally Posted by Finnius

Hey Arthur, are all your temperature observations from a coolant temp gauge or one of those fancy gauges that has a sensor bolted to the head?

Whilst we are on the topic of intercoolers... Does anyone know the purpose of the rubber wrapping on the metal turbo pipe from the turbo to the bottom of the intercooler (the pipe between the elbow and the straight coupling)? Is it purely insulation? Wouldn't the rubber just soak up the heat from the close proximity exhaust anyway?

My temp values are from a coolant sensor(VDO) connected to the thermostat bleeder nut. Temp range between 50-150°C(so I can't get any reading below 50°C).
I thought about getting a head bolt type sensor as an additional point to read from, but I checked the temp of the head at various points and it gets hotspots.
Up at the front I generally see the same mid 80's readings, thermostat housing itself reads identically to the sensor readings, and there are various hotter(5-10°C hotter) spots along the side of the head too.
The temperature estimates I've been quoting tho are from logged data. (my gauge system does data logging)

I've also been curious as to why the rubber on the turbo pipe?

Yeah i asked about the rubber on the turbo pipe, as mine is kind of ripped in places and was wondering if i could just cut it off and then buff the tube with a metal polisher!

Originally Posted by Finnius

Yeah i asked about the rubber on the turbo pipe, as mine is kind of ripped in places and was wondering if i could just cut it off and then buff the tube with a metal polisher!

not 100% but i would assume that the rubber cover on that pipe is to stop or insulate from radiant heat transfer from hot exhaust and turbo. otherwise you might pump hot air into you intake system.

i wanted to replace that pipe work in aluminium with heat sinks on it and have a heat shield on the exhaust side of it. then put some kind of bonnet cut out (louvre) to get cool airflow though there. probably for little gain but gives me a project.

Yeah a bonnet scoop over the exhaust side of the engine would be good. At highway speed, cool air would rush in and push the hot air out the bottom...

Wouldn't the rubber wrapping of that pipe just heat anyway though?

Originally Posted by AK83

Ah! I haven't explained tho that with the A/C on even in mild 30°C ambient temps, I've had over 100°C coolant temps(of course the dash gauge doesn't move).
I remember at about roughly 103 or 105° the dash gauge starts to climb, and reached the start of the red zone.

Other times I've had 'heating up' has been self inflicted in some way. And it's always the coolant bleeding process that I used to bugger up(or something).
But that makes sense.

With A/C off even in 40°C hot conditions I reckon(from memory) max coolant temp I've noted has been in the high 80's(87 or 88 or so), but always on a run. Slower running always sees my coolant temp drop

We had a few days in the low 30's about a month or so ago so I turned the A/C on just to see if the coolant would rise to some of the high temps I've noted previously, but have yet to see it at all.
The two differences between last summer and a month ago is that I haven't had the fan shroud on for a couple of months .. so I'm making my comments on that basis at the moment.
The other thing I have done was replace the thermostat. In the end was needlessly too tho.
I broke the 3 way bleeder thing between rad-coolant bottle and thermostat housing so I replaced it temporarily with a T piece to keep me mobile.
Since that temp job, I had a lot of trouble with the engine getting warm at all! .. as in 60°C temp. Turns out that bleed thing is needed for quicker warm up times(thanks to info from AULRO of course )
Anyhow, I changed my thermostat thinking it was stuck open.
Went from Waxstat brand to Tridon.
A major massive difference in the way they both operate tho. I popped both of them(and the cooler temp Tridon I also got) in boiling water.
The Waxstat thermo barely opens up(that is the flow through) whereas the Tridon opens up much more(ie. much more flow through). The difference between them is huge. Obviously the cooler running thermo opens up earlier but both the Tridons open to the same gap between valve and body. I'd estimate about 5-10mm gap .. whereas the Waxstat thermo only opens a mm or two.

FWIW too tho, I rarely use the A/C unless I'm sitting in heavy traffic and it's stifling, or on some dusty roads. Done that a few times last summer.
In slow crawl traffic, coolant never rises above high 80s, so the higher temps I've seen with the A/C on have always been on a run(ie. 80-100k/h or on some slow windy uphill dusty roads)

The over 100°C temp I panicked about was on a camp trip, car loaded heavily kids in car, car struggling up some of the hills. On the down slope it would cool down to the low 90's.
So I managed the A/C on this drive as I cottoned on to what was happening.
On the uphills sections I'd switch AC off (roughly) half way up to give the coolant a chance to not overheat, then leave the AC on as we crested for the downhills and level sections.

We have some 30 or so degree days coming up early next week here, so I'm keen to do more testing with it .. more than anything else .. to see if this fan shroud is actually helping with cooling at speed.

They say Friday is going to be warm again too(high 20's or so) and I usually take kids to school. It's all stop start driving along this tram infested road.
I'll remove fan again and double/triple check temps along the half hour each way drive .. and reply back again.

ps. I didn't remove my fan for cooling testing .. I was having trouble with the harmonic balancer and fan belt so trying to diagnose balance, level running and noises. Just happened that I also noticed my temps running normal with it off.
I always run the engine with the fan on .. habit I guess.

i did a run last year when it was 42C up to Cunderdin from Perth. 2.5 to 3hr drive through hills. had wife, dog, daughter, some light gear. i was doing the same. up hill air-con off and then back on at crest. wasnt the most relaxing drive. my temps ranged from 87 (normal temp) to 96C i think was highest when my EGT was about 650 for about 10-15 seconds. i think the avg was about 92 or 93C for that trip.

i think d1 generally run cool in normal driving and at normal ambient temp but then heat up quickly under load. possibly due to it being designed for english climates. i think even though can be annoying sometimes, a careful foot can manage temps.

other option is to get a better radiator, intercooler and turbo (with higher boost)

Originally Posted by Finnius

Yeah a bonnet scoop over the exhaust side of the engine would be good. At highway speed, cool air would rush in and push the hot air out the bottom...

Wouldn't the rubber wrapping of that pipe just heat anyway though?

not as much as metal. its quite heavy rubber and insulates against radiant heat. i would be confident in their reason for putting it there rather than speculate if it makes a difference.

with the louvre i was thinking more like the flush ones, similar to the side one on wrx. rather than get air pushed in, you let air flow out that comes from the front or under at speed and out the bonnet louve. would need to test air pressure spots over bonnet to see where best to put it. there is a thread on here about that and people's opinion about scoops etc. i think if you have a low pressure point where you put a scoop you would be getting air out rather than rammed in.

Originally Posted by Finnius

....
From what you say it doesn't sound like they are prone to overheating - perhaps even the opposite (if you have driven around with no fan with no obvious consequences!)

Todays drive to kids school. I'm estimating ambient temps this morning at about 20°C.
About 25mins each way.
Easy trip down .. passed tram early on, along the route easy free run to the school.
About 4 stops along the way, I reckon 5mins max at one of them.
Took fan off before I headed off.
Highest temp recorded was 81°C on the way down. Generally sat at about 80 once it warmed.
Very slow drive on the way back home tho .. long queue behind one tram.
Took at least 10 mins to travel 200 meters or so past the worst intersection.
Coolant temp on the way back again sat at 80-81, rose to 83 for a split second just after I cleared this very tedious intersection, and settled back down to 82 for a 2 min free run to the next set of lights.
Next set of lights are about 1 min beyond that with a free run at about 50k/h and coolant temp dropped to 79°C! ... but

So my assessment of my D1 at the moment is that the fan isn't really doing all that much. My observation of it for a long time tho is that it freewheels a lot anyhow.
Was bought new from Mario in April .. and in hindsight I don't think the old one was actually inoperative.

I have no idea on the overall history of my D1, but head gasket definitely looks like it's been done at some point. Previous owner hadn't done it, so one of the prior owners had for sure. One of those previous owners definitely towed something heavy as it had a brake controller fitted(I removed) ... so they may have worked the engine harder than I'll ever do. Engine did have green coolant when I got it, but I've drained it so many times since(many stuff ups and so on) .. but only run straight water ATM. But it's clean as a whilst. Doubly confirmed when I had to do my water pump the other day too.

Until I do a test run on a warmer day with engine under load and A/C on .. my assessment of the 300 Tdi is that it's not really prone to overheating unless something is amiss.

One thing I'm curious about too is the type of radiator each member has in their 300 Tdi D1.
I'm looking around various places .. ebay LR parts sellers and forums, and many seem to have a copper or aluminium rad with the silly plastic side tanks.
Mine has a full copper radiator(ie. copper side tanks).