My 1996 XJS overheats. I have learned previous owner used Barsleaks. How do I clean out the radiator, preferably without taking it out of the car?
Thanks!

 

You could try to flush it. The best would be to remove rad and bring it to a rad shop to have it professionally cleaned. Overheating is big enemy of your engine.
If you do it right the first time it will save time and money in the long run

 

It sounds as though the PO was trying to Stop the Radiator from leaking, without spending too much money in the process.

That being the Case, if it were me then I would do the job properly and take the Radiator out and then have it re-cored.

As has now already been said, overheating is a very big 'No No' with these Cars and if the Engine gets 'Cooked' then bad things can happen.

It really is beginning to sound as if the Radiator needs to come out before the overheating problem does some serious damage to the Engine.

The first thing to do is to get the cost of a re-core then you can decide but the one thing that I would not do is leave it as it is, or it could end up costing you a fortune.

 

Yep.

How do YOU recover?????, DRINK MORE.

The car recover??, NO shortcuts, SORRY, that is why you are in the current situation. Radiator OUT, professionally cleaned, and/or recored. Heater core flushed, MANY times, and the engine block also.

Replace ALL the coolant hoses (new clamps), and I mean ALL the hoses.

A new pressure cap would do no harm also.

Repeat this in about 15+ years times.

 

Unlike the V12, the AJ16 is more robust and not inherently prone to overheating. And the rad and cooling system is not particularly prone to clogging up. The biggest cause of a high temp gauge in the late 4 litre cars is corrosion and loss of the cooling fins in the lower third of the rad as a result of road debris being thrown into it. This leads to a lack of cooling when the car isn't moving.

Have a look at the fins in the bottom third of the rad, from the inside left of the rad from the engine bay. If there's a loss of fins, get the rad recored. Normal temp will then be resumed.

Good luck

Paul

 

Here is some interesting information from KWE;

Coolant Sealants - XJS & XJ from KWE Cars

 

Ptjs1. As Rod has stated the po used barsleak. That is what clogged his cooling system. Overheating is a problem for ALL engines.

 

That Story from KWE is the stuff of Nightmares, well done for posting that one, you have undoubtedly saved some newbie from making a big mistake.

 

Well, I suppose, one could conjure up some type of "flow test" by removing the bottom hose and adding water to the top at some visible rate. observe how long it takes for that??? That may show some indication of if and how badly the tubes are clogged rom whatever cause.


But, if clogged, a boil out, only might clear them enough to use. elderly cores rarely survive the classic rod out job.


New core or new radiator. The safe way. Caveat, a "cheap" core is just that.


Marginal cores may live in cold climes and fail utterly in the hot ones!!! Don't ask....


Alloy vs brass? Four row vs two row. Invitation to forum diatribe!!!


Carl

 

Lionrod,

The key thing first is to work out why the car is overheating before you start cleaning or flushing or anything else.

Bc xj said that your system was clogged but I noted that you didn't say that. You just said that the PO used Barrs Leaks and the car is overheating.

So, as mentioned you first need to establish the reason for overheating. It MAY be a blocked system, or it MAY be a leaking system or it MAY be corroded rad fins, particularly if it only is overheating at rest rather than on the move.

Good luck

Paul

 

Took radiator out, had it cleaned, seems okay but have high idle while driving so cannot tell if have high temp until I fix the idle.