When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yes, it is a Nissen. Replacement went pretty smooth except for breaking loose transmission coolant line nuts. Fill with coolant and start. Poised to add coolant at reservoir as sucked in. Within a few seconds coolant comes out of reservoir like Old Faithful. Shut done immediately. Dumbfounded until see transmissin fluid coming out of outlet in picture. Unlike XJs, on XKs this outlet is suppossed to dead end. No instruction packet came with radiator saying needed to plug. Actually kind of good this open pathway existed as immeditaely told me what was up. Opened thermostat tower and transmission fluid there. Figured eruption happened after initial coolant in system and transmission fluid totally filled system.
Yes, it is a Nissen. Replacement went pretty smooth except for breaking loose transmission coolant line nuts. Fill with coolant and start. Poised to add coolant at reservoir as sucked in. Within a few seconds coolant comes out of reservoir like Old Faithful. Shut done immediately. Dumbfounded until see transmissin fluid coming out of outlet in picture. Unlike XJs, on XKs this outlet is suppossed to dead end. No instruction packet came with radiator saying needed to plug. Actually kind of good this open pathway existed as immeditaely told me what was up. Opened thermostat tower and transmission fluid there. Figured eruption happened after initial coolant in system and transmission fluid totally filled system.
not a dead end on 4.0 XKR’s
on the XK8’s it might get plugged, it’s active on my 2002 XKR.
Radiator end Where the same line goes into the coolant reservoir.
sounds like you received a faulty radiator if the trans cooler leaked into the radiator and vendor should replace
I used these and a tie wrap to cap that off - been holding steady since I replaced the radiator several years ago. This used to connect to the expansion tank but they did away with it for some of the models. https://www.autozone.com/fittings-an...store_set=true
sounds like you received a faulty radiator if the trans cooler leaked into the radiator and vendor should replace
They will replace radiator free of charge or refund purchase price. Put doesn't cover fresh coolant, trans fluid and my time flushing and replacing. Trying to get definite answer if a used all aluminum Aston Martin is an exact fit. May go that way.
They will replace radiator free of charge or refund purchase price. Put doesn't cover fresh coolant, trans fluid and my time flushing and replacing. Trying to get definite answer if a used all aluminum Aston Martin is an exact fit. May go that way.
I missed the bit about the faulty radiator. Yes, get a refund. So, looking at the Aston Martin DB7, DB9, and V8 Vantage radiators, they seem to have near identical dimensions to ours. The mounting points seem to be identical, and the inlets for the radiator hoses seem to be in the same position and visually seem like they're the same diameter. However, a very clear difference I can see between the two units is how the transmission cooler lines are attached. The Jaguar radiator has a male fitting, whereas the Aston has a female fitting.
It's probably not too hard to convert the radiator to a male connection for the trans cooler. If you can buy a good used one at a good price, it will probably be the best bang for the buck radiator you can buy.
Ebay All Aluminum Aston DB7/DB9 Radiator Engine side
Ebay All Aluminum Aston DB7/DB9 Radiator Bumper side
OE Aston Radiator (Plastic End Tanks) Engine side
OE Aston Radiator (Plastic End Tanks) Bumper side
OE Jaguar Radiator Engine Side
OE Jaguar Radiator Bumper Side
Radtec All Aluminum XK8 and XKR Radiator Engine side
Radtec All Aluminum XK8 and XKR Radiator Engine side
Radtec All Aluminum XK8 and XKR Radiator Bumper side
Radtec All Aluminum XK8 and XKR Radiator Bumper side
So, in summary, I think the Aston Martin can be an almost directly fit. You may just need adapters for the transmission cooler lines. I think the Nissens radiator you bought came with the adapters you need because it might possibly be the same part as the one they sell to the Aston folk. There's only one dimension I can't visually tell in all these images and that's how thick the radiators are. They may very likely be the same thickness. The only other difference I can see between the Jaguar radiators and the Aston radiators are some mounting tabs on the bumper side for a bracket. That bracket, if I recall correctly, has the purpose attaching the radiator to the A/C condenser. You might be able to get away without that bracket? If not, weld one. It doesn't seem complicated.
IF you can find an all Aluminum Aston Martin Radiator for less than the price of a Radtec All aluminum radiator then that's most likely the best option on the market.
If you decide to get a refund on the Nissens radiator and want to try either the Aston Martin or the Radtec radiator, please report back to us. I think you'd be the first to try either option and it would be a great contribution to the wealth of information on this forum about the fit of either of those radiators.
Last edited by giandanielxk8; Apr 14, 2025 at 05:13 PM.
the aston radiator is an XKR radiator. db7 vantage, vanquish and all VH cars until the 08 model year use it. sticker is printed supercharged cars only
The XK8 can use the XKR radiator, just block off the thin spigot at the top left of the radiator that would normally connect to the expansion tank. What would be the side effect? That your XK8 would have more cooling efficiency and be less likely to overheat if all other cooling system components are in good working condition? I don't see problem.
Notice that in all the pictures of the radiators in my previous post, they all have a noticeably denser fin and core design than the Nissens, as seen below. I would prefer to be over-radiatored than under-radiatored. I don't get how Nissens has gotten away with under-speccing their radiator for years and nobody really seemed to have problems with it until now... Perhaps it's evidence of global warming?
Last edited by giandanielxk8; Apr 14, 2025 at 06:01 PM.
The XK8 can use the XKR radiator, just block off the thin spigot at the top left of the radiator that would normally connect to the expansion tank. What would be the side effect? That your XK8 would have more cooling efficiency and be less likely to overheat if all other cooling system components are in good working condition? I don't see problem.
Notice that in all the pictures of the radiators in my previous post, they all have a noticeably denser fin and core design than the Nissens, as seen below. I would prefer to be over-radiatored than under-radiatored. I don't get how Nissens has gotten away with under-speccing their radiator for years and nobody really seemed to have problems with it until now... Perhaps it's evidence of global warming?
I’ll throw out two factors that jump out for me:
1) there are more XK8’s than XKR’s. A lot more. The 8’s produce less heat, so the fin count of the Nissen product is not as important as it is for the XKR’s.
2) most people, and this is a total guess, have their X-100’s as a spare car, not a daily driver, and they don’t take it to the limit constantly.
So the shortcomings of the Nissen don’t get exposed as much as one might expect given the obvious differences it has when compared to the stock radiator.
1) there are more XK8’s than XKR’s. A lot more. The 8’s produce less heat, so the fin count of the Nissen product is not as important as it is for the XKR’s.
2) most people, and this is a total guess, have their X-100’s as a spare car, not a daily driver, and they don’t take it to the limit constantly.
So the shortcomings of the Nissen don’t get exposed as much as one might expect given the obvious differences it has when compared to the stock radiator.
just a theory.
Z
That's all probably true, BUT, in hot climates, on the XKR, even idling at a traffic light taxes the radiator severely. Most people who only have the idiot coolant temperature gauge would never notice.
@giandanielxk8 Thanks for all the research. I decided to return the Nissen to RockAuto for a refund. They cover return shipping. Decided to order a used XK8 radiator from a 2001 with 71k miles from Noma Auto Parts for $180 shipped. I've ordered from them before and have been satisfied. I thought about this Aston Martin one on eBay https://www.ebay.com/itm/266698327737 for a little under $500 shipped. Decided against because looks like some of the tabs bent and might need some modification to attach A/C lines. Some of the ones pictured in you post look to have painted or powder coated fins. That can't be the best for heat exchange.
@giandanielxk8 Thanks for all the research. I decided to return the Nissen to RockAuto for a refund. They cover return shipping. Decided to order a used XK8 radiator from a 2001 with 71k miles from Noma Auto Parts for $180 shipped. I've ordered from them before and have been satisfied. I thought about this Aston Martin one on eBay https://www.ebay.com/itm/266698327737 for a little under $500 shipped. Decided against because looks like some of the tabs bent and might need some modification to attach A/C lines. Some of the ones pictured in you post look to have painted or powder coated fins. That can't be the best for heat exchange.
Black paint/powder coating actually helps with the cooling because bare aluminum has a low emissivity (~0.05), meaning it’s not great at radiating heat via infrared. Black coatings, especially matte finishes, have high emissivity (up to ~0.9), making them much better at radiating heat away from the surface. So, a black powdercoat can dramatically increase the radiator’s ability to radiate heat—, which is particularly useful at low airflow conditions like idling or low speed, where convection is less dominant.
That being said, you can request them un-coated in bare aluminum. .
So I definitely have transmission fluid in my cooling system and possibly coolant in my transmission. (Reminds me of the old Reese's comerical, "you got chocolate in my peanut butter".) Haven't had time to open drain plug on transmission to check. After install radiator and before fire up want to remove as much transmission fluid from block by flushing. I know there s at least one engine block coolant drain plug and but can't find location. Doesn't seem to be in workshop manual. Any one have a picture of it or can provide an exact descrip of location.
So I definitely have transmission fluid in my cooling system and possibly coolant in my transmission. (Reminds me of the old Reese's comerical, "you got chocolate in my peanut butter".) Haven't had time to open drain plug on transmission to check. After install radiator and before fire up want to remove as much transmission fluid from block by flushing. I know there s at least one engine block coolant drain plug and but can't find location. Doesn't seem to be in workshop manual. Any one have a picture of it or can provide an exact descrip of location.
The drain plug is on the left hand side of the block at the bulkhead/firewall end. On LHD cars it is hidden behind the steering column joint so is very difficult to get at and will also be very tight. I would leave it alone and just drain the radiator or disconnect the lower rad hose as you are going to need to do a lot of flushing to clear the heater matrix which will not drain through the block drain anyway.
Don't forget that you can't just drain the gearbox through the drain plug and then refill it as it will also pour out of the level plug when you remove that. You will need to utilise the full engine-running refill procedure. Even there is any water in the bottom of the pan, it might also be in the torque converter and you cannot drain that. You will probably need to remove the pan, replace the filter, and do a couple of refill and drains to clear out any water.
The other problem is that the drain plug is in a raised boss so there is always a good quantity of fluid left in the bottom of the pan even when it is fully drained and that is where any water will be sitting. You could, very carefully loosen the drain plug and only allow a few mls to trickle out. if there is any water in it then you know that the pan has to come off. If there is no water, then it could simply be below the level of the raised boss.
The drain plug is on the left hand side of the block at the bulkhead/firewall end. On LHD cars it is hidden behind the steering column joint so is very difficult to get at and will also be very tight. I would leave it alone and just drain the radiator or disconnect the lower rad hose as you are going to need to do a lot of flushing to clear the heater matrix which will not drain through the block drain anyway.
Don't forget that you can't just drain the gearbox through the drain plug and then refill it as it will also pour out of the level plug when you remove that. You will need to utilise the full engine-running refill procedure. Even there is any water in the bottom of the pan, it might also be in the torque converter and you cannot drain that. You will probably need to remove the pan, replace the filter, and do a couple of refill and drains to clear out any water.
The other problem is that the drain plug is in a raised boss so there is always a good quantity of fluid left in the bottom of the pan even when it is fully drained and that is where any water will be sitting. You could, very carefully loosen the drain plug and only allow a few mls to trickle out. if there is any water in it then you know that the pan has to come off. If there is no water, then it could simply be below the level of the raised boss.
Richard
Climate control was turned off and only ran for a few seconds so think heater matrix clean. Transmission fluid did make it to reservoir. Why I want to drain from plug is because otherwise can't flush coolant without tranny spinning and likewise can't fill/flush tranny without engine running. I have a suction pump (the big kind like a standing bicycle pump) with a thin hose. Is there a way to snake down into engine? Other idea, if I hook a hose to reservoir cap (kind of like a reverse vacuum fill) will it flush out through water pump?
Climate control was turned off and only ran for a few seconds so think heater matrix clean. Transmission fluid did make it to reservoir. Why I want to drain from plug is because otherwise can't flush coolant without tranny spinning and likewise can't fill/flush tranny without engine running. I have a suction pump (the big kind like a standing bicycle pump) with a thin hose. Is there a way to snake down into engine? Other idea, if I hook a hose to reservoir cap (kind of like a reverse vacuum fill) will it flush out through water pump?
It's a tricky one. The first thing I would say is that some auto fluid circulating around the coolant system for a short time is not going to do any damage and you are going to need a proper rad flush solution to completely remove it. The auto fluid will rise to the top so I would start by removing any oil which is visible in the pressurised header tank, in the atmospheric tank (behind the righthand-side wheel arch liner) and by removing the plastic cap on top of the thermostat housing (coolant will probably pour out but this is a high point and will push out more auto fluid. The cap is a black plastic cap but it might be under a pull-off chrome trim). Most of the oil will now be out and you can safely run the engine short-term if necessary.
Coolant in the autobox is much less desirable and definitely needs removing completely. If you have any suspicion that the coolant has travelled in that direction, I would bite the bullet and drain the fluid completely. If there is any water / milkyness in the fluid, then you are going to have to remove the pan, clean it out, and do a couple of full flushes.
If there is no sign of coolant in the auto fluid drained out of the pan, I would rig up a short, small diameter, pipe in the form of an inverted U and wiggle this up through the drain hole so that it goes up and then bends down into the very bottom of the pan. If you can tilt the car on it's stands/lift so that the autofluid runs down towards the drain hole then that would help. Then suck out the residual fluid, possibly 300 mls or more, from the very bottom of the pan. If there is no water in this sucked-out autofluid, then you are in the clear and you can either refill the autobox using the standard engine running procedure or continue with a full pan removal, filter change and fluid refill depending upon the condition of the fluid which you have drained and when it was last changed. It must be changed every 60k - 80k miles.
Once you are sure that the autobox is clear of coolant, then turn your attention to repeated flushing of the coolant system by bringing the engine up to temperature until any residual oil is removed.
Richard
Last edited by RichardS; Apr 17, 2025 at 04:03 AM.
Radiator replacement horror story
