Thread: Under bonnet seals - warning - do not remove

Also, be very very careful when handling the hard plastic tubes from the coolant expansion tank to the throttle body. After years of heat, they are brittle and break easily, I broke mine in 3 places handling the expansion tank. A new one is $55.

Originally Posted by glenhendry

I made a silly mistake, and now I am paying for it...

Lesson: Do not remove any of the bonnet seals. I removed one of the two foam blocks at the rear corner of the bonnet where it contacts the firewall. I hoped that this would allow heat to escape when stopped, but I did not anticipate the drastic affect it would have on air flow while driving. It acted as a sort of chimney and hot air was channeled out the new hole instead of going under the car and caused the coolant reservoir to soften and then pop (under its 20psi pressure). Thankfully the missus pulled over and no major harm was done. The ABS reservoir also looked heat affected and a largish plastic duct that vents under the coolant overflow.

History: For a long while now I have been concerned about the under bonnet heat, especially relating to the fuse box getting baked for hours after the car is parked up, with the clam shell bonnet all sealed up like it is. Not only heat, but 'corrosive battery fumes' had also been mentioned in posts and I wanted a way to get the heat out once parked up. I considered a bonnet scoop but learned folks warned that they could have undesired consequences.

Question: can I use the ABS reservoir off an earlier model on my 2000MY HSE? I have one, and they look identical. I believe that it is off of a 1999MY.

The ABS resevoir is just that, a resevoir. It is not under any pressure and as long as the level sensor plug is the same (I think it is) there should be no difference. Whilst you have the new unit off give it a thorough clean. When I did mine I let it soak in a degreasing solution for a few hours then flushed it thoroughly with water, then leaving it in the sun to dry out for a couple of days. It is amazing how clean you can get them .

Gary

Mate

Sorry to hear about your dramas

The coolant overflow pipe is the same as the air hose, 6mm nylon. Or you could just run fuel hose the entire run.

55 bucks is ridiculous !

Steve

Thanks for the heads-up! Mine became detached and I simply glued them back with Loctite Superglue as a matter of course, not realising that their practical significance...

To answer your question 2, yes, it is normal to see coolant entering the overflow tank in the location you describe.

Originally Posted by glenhendry

I made a silly mistake, and now I am paying for it...

Lesson: Do not remove any of the bonnet seals. I removed one of the two foam blocks at the rear corner of the bonnet where it contacts the firewall. I hoped that this would allow heat to escape when stopped, but I did not anticipate the drastic affect it would have on air flow while driving. It acted as a sort of chimney and hot air was channeled out the new hole instead of going under the car and caused the coolant reservoir to soften and then pop (under its 20psi pressure). Thankfully the missus pulled over and no major harm was done. The ABS reservoir also looked heat affected and a largish plastic duct that vents under the coolant overflow.

History: For a long while now I have been concerned about the under bonnet heat, especially relating to the fuse box getting baked for hours after the car is parked up, with the clam shell bonnet all sealed up like it is. Not only heat, but 'corrosive battery fumes' had also been mentioned in posts and I wanted a way to get the heat out once parked up. I considered a bonnet scoop but learned folks warned that they could have undesired consequences.

Question 1: can I use the ABS reservoir off an earlier model on my 2000MY HSE? I have one, and they look identical. I believe that it is off of a 1999MY.
Question 2: do you all see water flowing (visibly) into the coolant expansion tank from the smaller hose underneath the tank (towards the front)? I never noticed that before. It comes from the inlet manifold via the throttle body.

Can l ask what the concern or concensus is with bonnet scoops? I've been considering one as a way to reduce the under bonnet temp.

Originally Posted by davidsonsm

Can l ask what the concern or concensus is with bonnet scoops? I've been considering one as a way to reduce the under bonnet temp.

HI

Given what was said in the other thread, I can't see that it is going to cause problems. As long as you take care while wading

Steve

Originally Posted by davidsonsm

Can l ask what the concern or concensus is with bonnet scoops? I've been considering one as a way to reduce the under bonnet temp.

The problem is that the bonnet scoop will cause an area under the bonnet with higher or lower pressures, and this may stop or hinder through the radiator.

I think the best option to cool under bonnet once stopped is to fire up the air con condenser fans (off the aux battery) for a few minutes on a timer.

Here is the bonnet scoop thread.