Cook an Egg on my Bonnet
#1
Cook an Egg on my Bonnet
After about 15 minutes of driving I could easily cook an egg on my bonnet. Is this normal for a 4.2 series 3? I recon I could fry bacon if I put it right on the cam covers.
I have done, new rad, new thermostat, all new hoses, all cooling sensors, and new coolant at the correct ratio. The temp gauge sits right where it should too.
Anyone else find this?
I have done, new rad, new thermostat, all new hoses, all cooling sensors, and new coolant at the correct ratio. The temp gauge sits right where it should too.
Anyone else find this?
#2
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Harry Dredge (06-28-2016)
#3
I'm assuming you are talking of one that is similar to new cars? That fabric sort of stuff that's pinned under the hood?
Also, Doug, I'd like to thank you for all the help you offer to everyone, you've helped me MANY times. My jag would not be on the road with out you! I'd buy you a box of beers if i could. I think a lot of people would.
#4
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The Series IIs and early Series IIIs had a spray-on type insulator--'bituminous' , yes.
Later Series IIIs has a fiberglass blanket pinned to the underside, as you say. I think it insulates better. But nowadays you can buy modern trim-to-fit under hood insulating material and/or your local Jag-specific suppliers might offer a pre-cut version. Years ago I bought a gorgeous pre-cut insulator from Coventry West in Georgia. It was a dense closed-cell foam, actually. It looked great and really worked ! I have to think other suppliers offer the same.
Also, Doug, I'd like to thank you for all the help you offer to everyone, you've helped me MANY times. My jag would not be on the road with out you! I'd buy you a box of beers if i could. I think a lot of people would.
Cheers
DD
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#5
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My car had the "blanket" type pad on the bonnet. It had detiorated badly. Looked like a moth eaten bear rug. I removed it. I've not missed it. The bonnet paint had a dullish area overt the left side. I attribute that to the exhaust manifold of it's former DOHC 4.2. Heat shield notwithstanding.
It might have served as sound insulation as well. I don't miss it a bit, and my bonnet's paint has not gotten any worse.
Partly because the present V8 is configured differently? Yes, I think so. Lower manifold location and split four to a side. More room above the engine enables better air flow. A DOHC takes up so much room
and leaves little space for air flow.
Bituminous 1 and, I thought my plan of using "bed liner' was original.
Another example of "nothing new under the sun"!!!
Still going to spray t some day, just for looks, the under bonnet paint doesn't respond to polish!!!
Carl
It might have served as sound insulation as well. I don't miss it a bit, and my bonnet's paint has not gotten any worse.
Partly because the present V8 is configured differently? Yes, I think so. Lower manifold location and split four to a side. More room above the engine enables better air flow. A DOHC takes up so much room
and leaves little space for air flow.
Bituminous 1 and, I thought my plan of using "bed liner' was original.
Another example of "nothing new under the sun"!!!
Still going to spray t some day, just for looks, the under bonnet paint doesn't respond to polish!!!
Carl
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Harry Dredge (06-28-2016)
#6
The catalytic convertor is a major contributor to the heat problem under the hood as it is tucked up high near the exhaust manifolds and radiates heat upwards never benefiting from "under the car" airflow. When I had my wretched 6 still in the car I installed a hollow out cat ,..it is now laying on the ground in my "Xj6 junk pile of parts" left over from when I did the V8 swap.
I think that the closed cell foam underhood pads with a silver coating would work best at keeping the radiant heat down. I have louvers which some like and some hate ( I happen to like them and they work) They are functional. Gradually I am sorting this old car out
I think that the closed cell foam underhood pads with a silver coating would work best at keeping the radiant heat down. I have louvers which some like and some hate ( I happen to like them and they work) They are functional. Gradually I am sorting this old car out
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Harry Dredge (06-28-2016)
#7
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Yeah, the cats do get hot. In Ca, BAR specifies that they be up tight
as in the original. A look at my Cadillac manual shows them up close to the manifold outlet.
But, when, the muffler guy and I conferred, we agreed, well back, away from the transmission. transmissions don't like heat. Got past the referee. Luck or else. Not a bad guy, just rassling with reg's.
ORTH, the Cat on my Jeep is a way back. Had to replace it early on to get past SMOG. Was bolted in, now welded. Same guy that did the Jag.
Bituminous, a scientific name for tar.....
Carl
as in the original. A look at my Cadillac manual shows them up close to the manifold outlet.
But, when, the muffler guy and I conferred, we agreed, well back, away from the transmission. transmissions don't like heat. Got past the referee. Luck or else. Not a bad guy, just rassling with reg's.
ORTH, the Cat on my Jeep is a way back. Had to replace it early on to get past SMOG. Was bolted in, now welded. Same guy that did the Jag.
Bituminous, a scientific name for tar.....
Carl
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Harry Dredge (06-28-2016)
Trending Topics
#8
Bituminous seperates
Harry,
I have a '77 XJ12L with a BBC. Hood is always cool or only warm to touch. Lizard Skin Ceramic Insulation cured my heat issues.
Spray-On Insulation - Automotive Insulation Coatings | LizardSkin
The "bituminous" separates from the metal, holds moisture, and rusts the bonnet from the inside out.
My prep included: 1)air craft stripper, covered with saran for an hour, removes easily with a plastic body putty applicator; 2) sanding; 3)Eastwood Rust Convertor; 4)Eastwood Rust Encapsulator; 5)Lizard Skin Ceramic Insulation.
For the purist, then you could add the factory style blanket insulation.
I have a '77 XJ12L with a BBC. Hood is always cool or only warm to touch. Lizard Skin Ceramic Insulation cured my heat issues.
Spray-On Insulation - Automotive Insulation Coatings | LizardSkin
The "bituminous" separates from the metal, holds moisture, and rusts the bonnet from the inside out.
My prep included: 1)air craft stripper, covered with saran for an hour, removes easily with a plastic body putty applicator; 2) sanding; 3)Eastwood Rust Convertor; 4)Eastwood Rust Encapsulator; 5)Lizard Skin Ceramic Insulation.
For the purist, then you could add the factory style blanket insulation.
Last edited by lickahotskillet; 03-14-2016 at 09:20 AM. Reason: missed a step
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#9
Thanks for the write up and photos! I'll certainly look in to this, very useful for future readers too.
At a minimum I'll put a new hear shield on the bonnet. Although the water trapped underneath sounds like something to certainly look into.
I also want to cook some breakfast on the hood before u fix it though :P I don't think many people have done THAT on a jag before. Too bad care about my paint so much
I almost want to
At a minimum I'll put a new hear shield on the bonnet. Although the water trapped underneath sounds like something to certainly look into.
I also want to cook some breakfast on the hood before u fix it though :P I don't think many people have done THAT on a jag before. Too bad care about my paint so much
I almost want to
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Harry Dredge (06-28-2016)
#11
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Cheers
DD
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Harry Dredge (06-28-2016)
#12
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I'm thinking Nix was painted with Real Automotive paint, perhaps still easily available in 1986, and any repair now would be that water based garbage, and I don't think I'd want to chance heat damage to it.
I've bought the blanket thing, but my car lacks the hangers inside the hood, so I'm looking at Clyde's post with Great interest!
(';')
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Harry Dredge (06-28-2016)
#13
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#15
Water pump is new (remanufactured) too.
I'll do the temp test again. Once I get my hood open haha, it got stuck closed the other day.
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#17
According to Dougs common repair list over on jag-lovers the "normal" operating temperature for these is about 80 to 90. I assume centigrade. Those numbers are from memory but close to what he had on there.
Added info: This one does have emissions control so no Cats.
#18
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I am with Doug. the elongated patch of less shiny Grosvenor
Brown on the bonnet of my 83 is over the left side, roughly
where the DOHC's exhaust manifold was. I attribute that to high
exhaust temps.
Elinor: as your car is a lump, as is mine, not only is the engine bay less crowded, but the exhaust temps are split and lower in the bay.
Less likely to damage NIX's gorgeous black.
Why would water based paint be not as good as the older solvent based paint. It is what is deposited and left after the solvent or water evaporates that matters.
I suspect there are some 'contact" glues that will attach the pad to the underside of the bonnet.
All:
Next time, I go on an extended Jaguar run, I'm gong to take the bonnet temp outside, with my palm and with my dandy little HF
sourced IFR. My interest is peaked. Why, I dunno???
And, to my way of thinking, it isn't coolant temp that matters as to bonnet temp, but ambient under bonnet temps, a combionatin of heat from the radiator and the alloy and iron of the engine, itself + exhaust, of course. But, exhaust is a major part of under hodd temp.
Water, As to the "tar" insulation. Not much in the engine cavity.
And, yes, when used under the car as under coating, once quite popular, it could trap water and make rust issues even worse, rather than protecting the steel.
Nice discussion, folks.
Carl
Brown on the bonnet of my 83 is over the left side, roughly
where the DOHC's exhaust manifold was. I attribute that to high
exhaust temps.
Elinor: as your car is a lump, as is mine, not only is the engine bay less crowded, but the exhaust temps are split and lower in the bay.
Less likely to damage NIX's gorgeous black.
Why would water based paint be not as good as the older solvent based paint. It is what is deposited and left after the solvent or water evaporates that matters.
I suspect there are some 'contact" glues that will attach the pad to the underside of the bonnet.
All:
Next time, I go on an extended Jaguar run, I'm gong to take the bonnet temp outside, with my palm and with my dandy little HF
sourced IFR. My interest is peaked. Why, I dunno???
And, to my way of thinking, it isn't coolant temp that matters as to bonnet temp, but ambient under bonnet temps, a combionatin of heat from the radiator and the alloy and iron of the engine, itself + exhaust, of course. But, exhaust is a major part of under hodd temp.
Water, As to the "tar" insulation. Not much in the engine cavity.
And, yes, when used under the car as under coating, once quite popular, it could trap water and make rust issues even worse, rather than protecting the steel.
Nice discussion, folks.
Carl
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Harry Dredge (06-28-2016)
#19
A couple of years ago JF had a couple of giveaways sponsored by
a vendor of hood liners. He passed away shortly after the last
giveaway.
But, they were well liked. He mentioned that they were cut from
aircraft firewall blanket material. It could probably be bought
from aircraftspruce.com
Make sure you ask for the free catalog, it is packed with goodies
that are hard to find anywhere else. No less than four choices
of english wheels, locking wire pliers in countless variations.
Everyone except LnrB of course. If hubby gets hold of that catalog,
it'll bankrupt the household.
a vendor of hood liners. He passed away shortly after the last
giveaway.
But, they were well liked. He mentioned that they were cut from
aircraft firewall blanket material. It could probably be bought
from aircraftspruce.com
Make sure you ask for the free catalog, it is packed with goodies
that are hard to find anywhere else. No less than four choices
of english wheels, locking wire pliers in countless variations.
Everyone except LnrB of course. If hubby gets hold of that catalog,
it'll bankrupt the household.
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Harry Dredge (06-28-2016)
#20
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Now that I think about it, not only are they split, but they're Much Lower in the engine bay, and partly hidden below the valve covers.
Why would water based paint be not as good as the older solvent based paint. It is what is deposited and left after the solvent or water evaporates that matters.
Next time, I go on an extended Jaguar run, I'm gong to take the bonnet temp outside, with my palm and with my dandy little HF
sourced IFR. My interest is peaked. Why, I dunno???
sourced IFR. My interest is peaked. Why, I dunno???
Nice discussion, folks.
Carl
Carl
My dad was a complete sucker for any new tool (gadget) to hit the market! He would have looked long and hard at that laser rust remover over in Off Topic.
I mentioned this catalog to husband just for fun, and he said some aircraft catalog or other is where he got the clecos I used to hold the floor together for welding! (The link below is to that specific post, not the whole thread.)
https://www.jaguarforums.com/forum/x...2/#post1102220
There's simply no surprising that man!
(';')
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Harry Dredge (06-28-2016)