Is there any pressure in the coolant jacket when the engine is cold ? This indicates combustion gases are still there under a bit of pressure, (it will diminish from when you see it boiling over as the engine cools). This is a good indicator of head gasket failure, but shops usually have electronic devices to check coolant for combustion chamber products dissolved in the coolant.

 

Fans are correctly drawing air from the radiator. I was wondering if plugging off the heater bypass would fix the problem. At the moment I replace the distributor with a pertronix unit and replace the ignition wires but I'm getting no spark so I believe I need to get a matching ignition coil which is on order. When I get the ignition system working and timed correctly, then I will continue to experiment with the cooling system to get it to operate at the correct temperature.

 

Will the 3.8 e type carbs and manifold fit on my series 1.5 68 E-Type 4.2 engine?

 

I did not look at this in detail before, but it looks like it would be ok. The overhaul kits for the SU HD8s are the same for 3.8 and 4.2 engines. Cylinder head interchangeable discussions in the past indicate the three pairs of manifold would also work. You may have to do something with the water outlets from the 4.2 head? I am sure some one has done this, you may try asking this question in a new thread. I pulled some notes from a 2011 posting that will be interesting to you, my comments are in red. It appears that the triple manifold is the key, not just the extra flow from the bigger carbs. Rgds David

 

Did you put the 420 triple manifold on an xke?

 

I did this with a 420 triple manifold and 2" SS Exhaust Headers on my 68 XKE S1.5. (I did not do a DYNO check), but “Seat of pants” results, indicated a huge improvement””

 

Im sure the headers had a lot to do with the power increase.

I am still awaiting the Pertronox coil arrival so I can continue to work on the engine.....ignition system replacement and then overheating issue. in the meantime I pulled one of my brake calipers off the front. What a strange-looking caliper. I thought the series 1.5 had the 3 piston calipers but mine came with 2 piston Dunlop caliper in the front. In order to pop the Piston out, what are you guys using to block off one side of the bore when applying air pressure to the brake line opening?

Also, I am reading that EBC green stuff is the best pad for a little better bite. Is this true?

 

"I thought the series 1.5 had the 3 piston calipers but mine came with 2 piston Dunlop caliper in the front. In order to pop the Piston out, what are you guys using to block off one side of the bore when applying air pressure to the brake line opening?
Also, I am reading that EBC green stuff is the best pad for a little better bite. Is this true?"

I just used regular linings, but changed them when they were worn halfway, without touching the rotors until they were worn to minimums. When I pulled calipers, I just rapped a large rag (two or three raps) around Caliper and blew the pistons out.
You can change the rear pads and parking brake pads by pulling rear seat/back and an access panels. Serious rear brake work requires dropping the rear suspension, which is best left for a long winter project, as there will be "dozens" of things needing doing, when the rear suspension is off the car.
When you have the rear suspension out, install the remote rear brake bleed hose kit, this will make life (under the car) much easier in future.

When my teen age son began to drive the XKE, he complained of brake fade in the warm months. Found he was in third between stop lights and heavy last minute braking boiled the moisture in the brake fluid.
The fix was to flush DOT 4 fluid annually, and install a set of quality drilled and slotted rotors. Rotors came from a Canadian company (aka China) and were less than the cost of having rotors pulled and skimmed. Better pads are probably a worthwhile investment in California summer traffic.
Rgds David

 

I took a break from working on the car. I wish I hadn't waited so long, but I am back now. To recap, I got my father's 68 2+2 in Nov 2018 after it sat for 33 years. I worked on it for several months. I rejuvinated the fuel system, and cooling system, but determined that the car was overheating after driving for about 15 minutes. I installed a Pertronix distributor and new spark plug wires, but was getting no spark. Fast forward to present time, I bought a matching Pertronix coil, figured out the odd wiring to the coil, and started the car right up after having it sit for a year. The engine runs really smoothly now with the hotter spark and electronic ignition. I had removed the drivers side brake caliper to inspect the brake system and determined that the bores and pistons should be replaced. The brakes actually worked fairly well, even though the car sat for so long. I have the bores/pistons on the way to me. In the meantime, the big concern is the overheating issue. The consensus in early 2019 when I was working on the car, is that the head gasket may be eroded away from sitting for so long, causing the engine to overheat. After the brake calipers are done, i plan to pull the head to see if the head gasket is blown and maybe the cooling passages are plugged. The cooling system was in pretty bad shape with a lot of corrosion on the thermostat housing, which I replaced. Any thoughts, before I pull that large head off the engine?

 

The most common cause of these Jags overheating is the rad. Sometimes the engine block water passages are clogged as well, but if you pull the rad and get it tested then a simple recore could fix the overheating. I went with a coolcat rad and that took care of the overheating for me.

 

I had the radiator rodded by a radiator shop, so its flowing 100 percent. The fans are working also. Im thinking that a compression test may reveal that the head gasket has eroded.

 

Have you had the coolant checked for combustion gases ? Also a pressure test of the coolant chamber ? Have you taken off the water pump and checked the pump impeller ? I'd do this before pulling the head. You might also try looking in the combustion chambers with one of those viewing devices via the plug hole. If water is getting in it washes the pistons so they look clean instead of black.

 

I have not checked coolant for combustion gases and I didnt pressure test the cooling system. Water pump is new tops of the Pistons are not black because the engine was rebuilt before the car sat for 33 years.

 

I used a block tester, and tested the coolant for exhaust gases. The test showed no exhaust gases as the test liquid remained blue. I tested from the pressurized coolant overflow tank on the firewall. Then after letting the engine cool down a little bit I opened up the cap on the radiator and withdrew some of the coolant and then started the engine and let it idle and warm back up again and then tested the radiator itself for exhaust gases and the test liquid remained blue. My conclusion is that it's not a head gasket that's causing the overheating. The only thing left that I can think of is that the block and or head may have the cooling passages blocked since the car sat for 33 years. Something else I thought about. Even though I had the radiator completely cleaned out, from running the engine it may have gotten plugged up again from Gunk inside the engine. Gauge needle still reads about on the "N" of the "Normal"

 

Okay this morning I used my infrared temperature sensor with laser sight to take temperature readings as the engine was idling. At about 8 minutes of idling, the top of the radiator was about 80 degrees Fahrenheit and the bottom was 70. After 12 minutes the temperatures went to 106 and 89 respectively. At 15 minutes both temperatures were the same at a hundred and fifty degrees. Fans came on at 15 minutes. A 22 minutes the temperature was about 158 degrees both at the top and bottom of the radiator. As an experiment, I shut the engine off but then turned the ignition key to on to see how long the fans would run and they ran over five or six minutes before I started the engine again so that the battery wouldn't wear down. I let the engine idle until severe overflow occurred at the expansion tank. Top and bottom of radiator was 205 degreesF. Temperature sensor was about 188 degrees. Temperature gauge read at the N of "normal" and never went above that. When I shut the engine off but kept the fans running, top of radiator was 205 bottom of radiator was 157 and temperature sensor was 188. Upper radiator hose was pressurized. Any thoughts?

 

Temps look good, are filling overflow tank to full? Put in driveway and watch temps and let overflow until it levels off. Usually tanks are half full. Just a thought, as Normal and 205* is good. Only overflows when stopped, still thinking too full of coolant.

 

Since I know that the head gasket is fine, my thoughts are that the block or head have sludge in it from sitting for 33 years. I tried to power blast it and clean things out last year when I was working on it. I'm sure I made progress on it but it seems as though there was more to do. The best thing would be to remove the head and clean out the cooling passages. However I made another breakthrough yesterday. I noticed that the coolant that would severely overflow had a brownish green color to it. Also I noticed sediment in the little overflow bottle that I put next to the expansion tank.

On a hunch, I opened up the block drain on the rear driver side and the coolant just barely trickled out indicating that there was more blockage. I opened up the radiator cap, and then I removed the block drain valve and put a power nozzle up to the opening and blasted water through until the water overflowed out of the top of the radiator. I kept the water there until it was clear. When I removed the power nozzle, the water flowed freely out of the block drain opening.

I know tap water is a big No-No but I knew that it wouldn't be staying in there too long and if the benefit of clearing out the block actually works, in the detriment of having tap water temporarily is worth it. I installed the block drain valve and shut it off. Then I topped off the system with water. I only put a little bit of water in the expansion tank, maybe 10 ounces or so. I started the car and let it idle. I occasionally revved the motor to circulate the water. This time the water temperature gauge got to the upper part of the white section. It didn't even make it to the part that says "normal". I let the car idle and occasionally raising the RPMs and did this for over 30 minutes without any water overflowing. The expansion tank was warm but not hot. No coolant leaked anywhere and the upper radiator hose was firm to The Squeeze. When I shut the engine off there was no gurgling or boiling sound. That was a pretty exciting breakthrough.

The issue now is that the fans stay on way too long.....12 minutes after turning off the engine but leaving the ignition switch on. Radiator header temperature was about 105 degrees F when the fans turned off, much higher than the factory specifications of around 150 deg F. This leads me to believe that the otter switch is sticking and probably has to be replaced.

This weekend I will flush the block more and possibly remove the radiator and backflush that to get any sediment out that may have gotten in. I will also remove the otter switch and bench test it in a pot of hot water to see if it operates correctly which I suspect it is not. I'll keep you all updated.

 

The XK engine was notorious for bad coolant circulation at the back of the block and crud would build up there. When I flushed out a bare block in the 80s, it was the long stud type so had core plugs opposite each stud, plus a little one towards the upper rear RH side. I also removed the plate at the back of the block. The amount of crud that came out was amazing. It could be this causing your overheating. Also was the water pump impeller a reasonably tight fit in the timing cover chamber ? I have a feeling Jaguar changed the diameter of the chamber, (larger) to get more circulation, but when this was done, I don't know.

 

The water pump did not seem like an unusual fit when I installed it last year. Just to clarify, the car never overheated, but it was overflowing substantially out of the expansion chamber. The temperature of the coolant was well within the normal range. So perhaps the hot spots in the engine created local overheating of coolant which forced it out of the expansion tank, similar to a volcano. I drove it around for about 15-20 minutes in stop-and-go traffic today and it was perfect. No overflowing, and the temperature gauge read in the middle of the white area which is below the NORMAL lettering. Before it would have definitely overflowed.

change of subject. The car has an automatic transmission and there is a rod which connects to the transmission via a linkage to the carburetor. I disconnected it because it was making the throttle stick, but I will try to work on it so that it moves more freely and does not affect the throttle control. My question is, what does that Rod connection do? I noticed the car does not shift into 3rd gear. Perhaps that has something to do with it. Again this is an automatic transmission equipped car

 

"The car has an automatic transmission and there is a rod which connects to the transmission via a linkage to the carburetor. I disconnected it because it was making the throttle stick, but I will try to work on it so that it moves more freely and does not affect the throttle control. My question is, what does that Rod connection do? I noticed the car does not shift into 3rd gear. Perhaps that has something to do with it. Again this is an automatic transmission equipped car"

Yes that is what tells the transmission your throttle position... When you tromp the throttle, the transmission will down shift for passing. New cables are available and not too difficult to change.
Rgds
David