Hello all, Just posting some pics of my recently acquired XJ6 before I start to do any work on it.
So far I have removed and cleaned the fuel tanks, cleaned up most of the electrical connectors, reverse flushed cooling system (car had new radiator but PO put water instead of coolant and it was all rust).
No thermostat(should I install one?)PO installed two electrical fans which work constantly.
Got the car running, but it is overheating. Compression averages 190 psi, no water in oil or oil in coolant. What could it be? Any suggestions?)
I would like to get the overheating resolved before I go any further.
I also have to crank the engine for about a minute or so to get the fuel system primed. Fuel system pressure bleeds down overnight. I think I need to replace the one way check valve in the boot.
Well, I will overcome these issues one at a time, heeding the advice i read on your excellent forum.

 

Welcome!!!


Lotsa help here.


Nice looking car.


Solve the overheat ASAP. Failure to do so can be a disaster!!


Removing the thermostat is misguided effort to solve over heat. Probbly makes it worse !!!!


1. Debris between radiator and AC condenser ?


2. Poor maintenance and clogged radiator core?


Running the Efans continuously? A necessary bodge?

 

@JagCad: Thought I read somewhere on this forum about not eliminating the thermostat. I will be attending to the overheating issue as a #1 priority

 

If there was just rusty water in radiator I will bet it is plugged at bottom.
Take it out and get it to a radiator shop or replace it

Do not remove the thermostat and run without it. The car is meant to operate at a certain temperature. The ECM reads the engine temp and sets fuel ,..timing,..etc based on engine temps.

More importantly if I were you I would be after the rust first. Especially around the windscreen corners. Be prepared to remove the windscreens to do a proper repair.

As well, using only water - no rust inhibitors is a factor when it comes to head studs rusting deep inside the engine. The studs get weakened and cylinder head gaskets fail.

The fans are running probably because they are wired in conjunction with the ignition circuit. Key on = fans run. You will need a temperature switch wired into the ignition circuit THEN they will activate the fans when a set temp has been reached.

Been there.. done that...

 

Regarding the rust in the cooling system, I reversed flushed the system, poured in 2 gallons of evap-o-rust and topped of the cooling system. I then ran the enging to circulate the evap-o-rust throughout the system, i then let this sit for 2 days. I then drained the evap-o-rust out (it can be used again) and reversed flushed the system a second time. I removed the thermostat housing, (that's when i discovered the thermostat was missing) System was flushed using a high pressure water pump. i have used this many times with total success. As stated previously, a new radiator was installed, but filled with water and was left sitting since 2005, in a garage cause the PO could not get it to start. So the rust was not crud but caused by water sitting in the block for 10 years. Be that as it may, I will be trying to diagnose the overheating issue in the next couple of days.

 

Hello, Sanchez, I see you found your way to our playroom.
Welcome from ElinorB.
(';')

 

Inexperienced novice here. I have some vague feeling that if the engine running too lean it runs hot?? Anyone else here Got any ideas? Maybe fuel pump not supplying enough fuel?? I am probably completely wrong but it might be a possibility? ??????

 

I installed a new fuel pump and fuel pressure regulator when i serviced the fuel system. the fuel pressure is somewhere between 40 and 50 psi at idle, so it's within specs. I have not driven the car as yet. the overheating happens at idle when left running for 20 to 30 minutes with both e-fans running. I personally don't think it is a lean mixture, but then again who knows. i am waiting for some of the gurus on the site to chime in. BTW ignition system is a tad on the advanced side but not enough to cause an overheating problem. I am going to install a thermostat and put a fan in front of the radiator to simulate airflow as when driving to see if it makes a difference.
Thank you LnR for your welcome. I have been following your posts.

 

Welcome aboard......we are up and about down here now.

 

Yes, you may need a new check valve.....but even with a faulty check valve the rail should pressure almost instantly. Like, 2-3 seconds.


Cheers
DD

 

A bit high, really. Spec is 36 psi while cranking....and from experience I know that it's about that when running. I wouldn't worry much about 40-ish psi but if you're getting up to 50, that's too much




What are your ambient conditions?




You might wanna check for *exterior* radiator clogs. Common on these cars. Debris accumulates between the radiator and the condenser. I've seen some where a full 30% of the radiator's cooling surface is totally clogged with debris

Cheers
DD

 

When I took my radiator out, at first glance, there looked like a nest of leaves down there.


Also, To start, put the transmission into "reverse" and turn the key to "crank" for 30 secs. This will pressurize the fuel system. Then start as normal.

 

@ Doug: Ambient temperature- Brutal 97 F feels like 102F.Extremely high humidity. But that should not matter, my other cars not overheating under the same condition.
Fuel Pressure: inadvertently wrote 40-50. it's more like 35-40 psi.
Radiator: shiny new. PO said he replaced it prior to parking up the car due to a no start condition and it looks that way. No debris between condenser and radiator. I failed to say that I removed the radiator and used a pressure washer to clean the fins of the radiator, AC condenser and oil cooler. I am wondering if the aftermarket e-fans are pulling in sufficient air. They could be some cheap brand with a low CFM rating.
To all others who chimed in: thank you for your input. I will be taking all of the advice given and will let you all know how it goes.
To the member who suggested that i do the body work first, i would rather get the car mechanically sound then do the body work. My take is why have a nice looking car that don't run right.
Anyway, since i am a little frustrated about the overheating, i left that alone and did some work on the suspension and brakes.
PO had told me that the car was serviced by a Jaguar tech in New York prior to the car being driven to Florida. He was speaking the truth. there were a lot of new parts on the car. tie rod ends, brake calipers, brake pads, steering rack rubber boots, rear shocks, and a work order found in the glove box to "prove" the same. I was going to put grease but at one stroke of my grease gun new grease came out. Everything seems nice and tight on the suspension. Funny thing happened though. The car has five new tires but dated 2004 and i knew that i would have to replace them. I lowered the car and moved it out of my garage and one of the tires exploded. They are all dry rotted. see attached pic.

 

First, and I should've asked sooner, how hot is the Jag getting, exactly? Some people consider 'overheating' to be boil-over. Others consider any upward movement of the temp gauge to be overheating.

Even if everything is 100% these Jags have only so much cooling capacity....and it isn't overly generous. So, ambient temps are part of the picture.

Idling for 20-30 minutes in 97ºF ambient conditions is pushing things just a bit for these cars. I would expect to see the gauge move up, at least.




Sounds very plausible. Driving the car will help determine this or your idea of a big fan in front of the car.


Cheers
DD

 

By the way, when you go to replace the thermostat make sure to get the correct type with the rear bypass disc. Most like to use Waxstat brand but they are not always easy to find. Stant 45598 or 13398 have the disc, as I recall.

You'll also want one with the steam relief hole. If not, it's an easy fix with a 1/8" drill


Cheers
DD

 

Yeah, 20-30 minutes at idle is a strain on any car. Some handle it better than others, though. But, in real life, the situation can exist in heavy traffic. So, lack of air movement might be a contributing cause. A rough test of the efans so as to put a hand in front to feel the "pull". It should be rather vigorous.


And, the mount should be in such a way as to prevent any flow around the shroud.
And, the shroud itself should mask all the fins. If not, the radiator isn't functioning fully.


And new isn't always great. Cheapo cores and radiators are skimpy on tubes and fins. Heat transfer diminished. Source?


Are he fans marked with ID's. Straight bladed or curved bladed . Size? A bit of Google might find the specs.


I suspect that the installation of a proper thermostat will go along way. When you install safe tires, a spin might tell a lot.


As your fleet is impressive, you are clearly not a neophyte.


Welcome!


My car is a lump. Lost the DOHC to extreme heat. I am extra touchy about that now.


Carl

 

I installed a thermostat and ran the car for 1/2 hour, temp read about 100C. (pic 2)Placed fan in front of grill and the temp dropped back to 90C.(pic 1) Prior to this it would be almost at 130C. I am keeping my fingers crossed. I will cycle it a few times to see what happens. Also, the PO connected the fans to the power wire on the diode pack.(pic 3) I will rewire the fans thru another switched source.

 

I hope the new stat does the trick for you.

My 84 XJ6 has an aftermarket temp gauge, but I've never understood the stock gauges on these with the needle being in the green (meaning 'ok' to me) all the way to about 125C/257F. I get worried at 100C.

 

Yeah that green past 90 C sure is misleading!!!!


I forgot to mention two aids for an engine running hot in stop and go traffic on a hot day.


1. Pop the hood/bonnet to the safety latch. A great assist in moving out hot air.
2. Off the AC and on the heat. A bit tough, but the heater matrix aids as a small radiator.


Nice car, some work will make it top notch.


Carl

 

That green band on the gauge isn't one of Jaguar's finer moments, that's for sure. Another prime example of "....an interesting design feature"


Cheers
DD