The car ran at normal temp then suddenly soared to hot in seconds.
The top hose felt hot and was expanded; the bottom hose was cool
and soft. Lack of flow? Changed thermostat. Same thing. Fixed
up without thermostat at all on theory that replacement stat was no
good - same thing. Mechanic thinks radiator is no good. Radiator
shop says this a baffle type radiator and baffle failure is
likely. Jag dealer has EIGHT of the danged radiators IN STOCK!
Why do they need so many in stock, one wonders…
Apparently this radiator cannot be repaired either at least not
around here.
Is there anything else that could cause this problem, other than a
defective or plugged up radiator?–
DonXJS
Pleasant Plains, IL, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from DonXJS sent Wed 2 Apr 2003:
I’ve seen it listed here where the water pumpm causes very fast
temp increase, and that the original XJ8 water pump is prone to
failure. The replacement is supposed to be better. Check the
archives, I think Pascal reported something like this.–
The original message included these comments:
The car ran at normal temp then suddenly soared to hot in seconds.
–
Jack XJ8L 1999
York, PA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Don’t change the radiator. Pull the water pump and check the impeller. The
early pumps had an impeller prone to failure, the fins flake off until
there’s none left and the increased heat of overheating speeds up the
process.
Regards,
Joe----- Original Message -----
From: “DonXJS” djhan486@aol.com
To: x300@jag-lovers.org
Sent: Tuesday, April 01, 2003 8:33 PM
Subject: [x300] 98 XJ8 overheating
The car ran at normal temp then suddenly soared to hot in seconds.
The top hose felt hot and was expanded; the bottom hose was cool
and soft. Lack of flow? Changed thermostat. Same thing. Fixed
up without thermostat at all on theory that replacement stat was no
good - same thing. Mechanic thinks radiator is no good. Radiator
shop says this a baffle type radiator and baffle failure is
likely. Jag dealer has EIGHT of the danged radiators IN STOCK!
Why do they need so many in stock, one wonders…
Apparently this radiator cannot be repaired either at least not
around here.
Is there anything else that could cause this problem, other than a
defective or plugged up radiator?
DonXJS
Pleasant Plains, IL, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
waterpump… one of the (few) weak parts on the AJV8. far more likely than
the rad. they probably stock the radiators because it’s the first thing
that goes in a collision…
pascal----- Original Message -----
From: “DonXJS” djhan486@aol.com
To: x300@jag-lovers.org
Sent: Tuesday, April 01, 2003 8:33 PM
Subject: [x300] 98 XJ8 overheating
The car ran at normal temp then suddenly soared to hot in seconds.
The top hose felt hot and was expanded; the bottom hose was cool
and soft. Lack of flow? Changed thermostat. Same thing. Fixed
up without thermostat at all on theory that replacement stat was no
good - same thing. Mechanic thinks radiator is no good. Radiator
shop says this a baffle type radiator and baffle failure is
likely. Jag dealer has EIGHT of the danged radiators IN STOCK!
Why do they need so many in stock, one wonders…
Apparently this radiator cannot be repaired either at least not
around here.
Is there anything else that could cause this problem, other than a
defective or plugged up radiator?
DonXJS
Pleasant Plains, IL, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from DonXJS sent Wed 2 Apr 2003:
Ditto on the water pump. I had the same thing happen to my '98
while cruising down the interstate on a 98 degree day last summer.
In my case, the top radiator hose and clamp were soft enough that
it blew off of the radiator and I also lost all of the coolant.
The heat also softened the plastic thermostat housing and cap which
lead to several other small leaks in the system after the pump was
replaced. It took a while to find them all, but all is well now.–
The original message included these comments:
The car ran at normal temp then suddenly soared to hot in seconds.
The top hose felt hot and was expanded; the bottom hose was cool
In reply to a message from DonXJS sent Wed 2 Apr 2003:
aDDITIONAL INFORMATION:
If there is heat - plenty of it - to the heater core, doesn’t this
mean that the water pump is getting it there? That’s primarily why
we think it’s the radiator, I guess, along with the other symptoms
as described. Thought about the pump, but then if there’s heat to
the heater core…–
DonXJS
Pleasant Plains, IL, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Pascal Gademer sent Wed 2 Apr 2003:
Your '98 XJ8 has a Nikasil engine. I’ll spare you the details, but
overheating is quite possibly the worst thing that can happen to
Nikasil. If you ever notice it overheating again turn the engine
off immediately and ask questions later.–
The original message included these comments:
Subject: [x300] 98 XJ8 overheating
The car ran at normal temp then suddenly soared to hot in seconds.
–
Jason F.
Dallas, TX, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from JasonF sent Wed 2 Apr 2003:
Although I have never seen such a case, a completely clogged water
path in cylinder head could produce the condition described. I
have seen many many cases of partially clogged cylinder head
coolant path causing pre-ignition.–
x300@'95XJ12
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Don’t know about the V8, but on the X300 the heater core has it’s own
separate pump which could maybe pull enough hot water through even if the
main pump was shot.
fwiw - Jez> If there is heat - plenty of it - to the heater core, doesn’t this
mean that the water pump is getting it there? That’s primarily why
we think it’s the radiator, I guess, along with the other symptoms
as described. Thought about the pump, but then if there’s heat to
the heater core…