E39 Engine Bay Heat Dissipation

[saat]

I realized that I have been having some persistent problems with different parts in the engine bay. I suspect that it is due to poor heat dissipation. The follwing is a list of items that I can remember.1. Windscreen washer tubing ALL hardened and crumbled.2. Water catch situated on the bulkhead crumbled to pieces.3. ABS controller give a fault code only when hot.4. Second pair of angel eyes when the inner plastic mechanism hardened and broke off.5. Windscreen washer bottle cap softened like jelly.6. Cracked radiator.7. Overflow tank changed due bleed valve stuck - found that seal melted.Lets compare notes. Mine is a 2001 E39 525i.

 

[affan66]

you're in heat, brother. I mean, your car is. You need to slow down, I think.

Perhaps, you should check your fan clutch. maybe it's not working in tip top condition and heat could not dissipate fast enough. Have you tried the rolling newspaper stop the fan method to check the fan clutch?

 

[saat]

Dah check, feels OK. Fan strong almost took off my hands.

 

[affan66]

Coolant used?
Last flush?

 

[fabianyee]

That has been a problem for the 6 potters even in the E34.... The engine bay is compact and there's no hot air outlet... hot air is trapped especially in stop go traffic that we encountered every single day.

 

[mack]

there is only one way to solve that - cut a hole or two on the bonnet...

 

[bimmerman]

Originally posted by mack@Jan 17 2005, 01:12 AM
there is only one way to solve that - cut a hole or two on the bonnet...

I've actually considered that! But not just cut a hole. It can be very nice if done right. Like an inverted airscoop. Not sticking out but sunken in.

I had a Merc123 with a Toyota 1G-GT Twin Turbocharged engine once. The car was seriously fast even for a tank of a chassis. But problem is everytime I encounter start stop traffic the car would overheat and I get all the problems you get. Hoses harden and crack, radiator leaking and bla bla bla. I was recommended an airscoop but I doubted it would help at all. Then one day a friend gave me a Pajero airscoop and I said what the heck and installed it. Guess what? Never had the temperature reach 80 degrees even in a crazy 2 hour long jam! Not kidding you. The hot air needs to escape.

Anybody got any nice airscoop ideas for BMWs without spoiling the cars aesthetics? Z3 Shark gills at the sides? I've got some pictures of some 5 series cars and I'll post a few pictures later.....

 

[wkwoo69]

Gosh, the heating prob is something new. Hamann's current style is NACA-style ducts on the bonnet (think Lambo Countach / F40 - the triangular one), but it is pointed outwards, i.e. for flow inwards. What you could do is point it backwards, for venting.

There's no doubting the efficacy. You can actually see the wavy distortion looking through the heat rising through the vent from inside the car.

You have to be extremely careful where you cut the bonnet though, due to water. What you could do is to zip tie some clear plastic below the hole to act as a water funnel. I've seen this on WRXs (which has two vent holes but are covered from the factory) and it looks tolerable because its clear plastic. Alternatively, get the duct tape handy for rainy days...

I find that the sound deadening felt used in my car is perhaps too effective for blocking heat as well - the middle of the bonnet is stone cold after a long drive (at night). Maybe you should consider removing it, so some of the heat can dissipate through the bonnet? But the downside is increased noise, and uncertainty as to how much temp change can be attributed to the bonnet.

 

[wkwoo69]

BTW, the Z3 vents (including M) are fakes. The new M5 apparently not. I guess if you do it, you'd need to fit a channel there. I wonder if a larger fan (maybe from an eight cylinder?) would help?

 

[CAJ19]

I removed the resistor on the aux. fan and hook-up direct. A little noisy, but the cooling is good. Never had any heating problems. Air-con ice cool. Maybe the fan will not last as long as it is running at full speed, but what the heck, stuck in jam and fumming mad with the heat, top of it all worrying sick that your engine may overheat. Too much stress.

 

[bimmerman]

Originally posted by wkwoo69@Jan 17 2005, 07:20 PM
Gosh, the heating prob is something new. Hamann's current style is NACA-style ducts on the bonnet (think Lambo Countach / F40 - the triangular one), but it is pointed outwards, i.e. for flow inwards. What you could do is point it backwards, for venting.

There's no doubting the efficacy. You can actually see the wavy distortion looking through the heat rising through the vent from inside the car.

You have to be extremely careful where you cut the bonnet though, due to water. What you could do is to zip tie some clear plastic below the hole to act as a water funnel. I've seen this on WRXs (which has two vent holes but are covered from the factory) and it looks tolerable because its clear plastic. Alternatively, get the duct tape handy for rainy days...

I find that the sound deadening felt used in my car is perhaps too effective for blocking heat as well - the middle of the bonnet is stone cold after a long drive (at night). Maybe you should consider removing it, so some of the heat can dissipate through the bonnet? But the downside is increased noise, and uncertainty as to how much temp change can be attributed to the bonnet.

Yes, water is going to be a huge concern and where you place the air vent requires very careful consideration. Even a spoonfull of vater trickling into your engine cover will make it's way into a spark plug hole. Even driving through a light drizzle will cause water to accumulate into a stream and eventually flow into your sparks as well. Hmmm... looks like the only feasable way to vent is through some gills. Anyone know where I can buy some gills?

 

[Tohsan]

My E39 528 today suddenly become overheat when i left the engine on for half an hour without moving. Then i quickly shut off the engine once i saw the temperature gauge hit the "red" zone. After I left the engine to cool off for about 2 hours, then I open the radiator cap, suprisingly, there is no leakage of water, and i start the engine again and further check the engine fan is working perfectly well too.
Is there anyone suffer the same problem similar mine? Any solution for it, or is this the common problem for this car.

 

[Lee36328]

Yeah, the recent hot weather has caused some heating problem for me too.

Watch that temp needle guys.