I'm new to the site, bear with me. Bought 95 Disco with motor noise (history of running hot and not starting), opened er up and found bad head gasket, among other things. Renewed heads, block, crank, valves. New bearings, new composite gaskets, basically everything but the rings. Mechanic knows little of the engine or LR systems, assembled the thing three times, something new each time, hence block repair and use of tin gaskets the first time around, to say nothing about the broken piston discovered at the last and 3rd build-up! etc. All built up now and there seem to be 4 problems, car (1) overheats on long climbs (do we know at what temp the electric fans come on?) and (2) there is a pronounced, intermittent "tick or tap" at lower RPM's. It's seems louder than a lifter and seems centered in the motor, but unable to localize. Could a valve be touching a piston? ( I am afraid to let the mechanic back at it for fear of what else he might screw up! (3)The other strange thing is that the temp gauge goes to center position (I understand it stays there until 110C is reached and then continues it climb into oblivion) and then started to indicate a cooler temp when it should have continued climbing assuming I had reached the 110C. I assumed the gauge was somehow reading backwards after 110 and shut the engine down for 30 minutes. There is no thermostat in the car and it throws a code 14 (coolant temp), although I have run the traps with the sensor using known values of hot water vs. resistance readings. I'm not big on swapping parts to troubleshoot, any idea's? I suspect that the sensor is actually bad even though the resistance values all check, but parts are unreasonably expensive here, so I have been waiting. (4) Idle is lumpy, but only sometimes, almost impossible to start engine when at operating temp, sometimes. I am sure minimum idle is not properly set, although somewhat close, as there seems to be no consistency as to how this engine runs at idle. We swapped out the stepper for another used one, seemed to improve the situation, but the thing is wearing me out, been two months in process. Help!

 

1. Electric fans normally come on with AC, or at 212F. Be sure they and main fan suck air toward the grille (like a plastic bag).

2. If radiator is sludged, the bottom rows will be much cooler than top. More than 10F difference top to bottom on fins would indicate this. The rad is a copper brass unit, and an old school shop can unsolder the side tanks and rod out the calcium.

3. The viscous clutch should feel firm when spun and released. Feel like mud inside. Spins less than 1 revolution. If it free wheels, the clutch has lost the fluid inside.

4. Needs a thermostat. That helps keep water in the radiator long enouugh to get cooled off. I run a 180F one in my D1. Spring end of thermostat goes inside the motor.

5. Get an infrared thermometer that you point at things to double check temperature - use the thermostat housing as the refernece point.

6. You can clean the MAF sensor with made-for-MAF-sensor spray cleaner, nothing else, and only do when stone cold. IACV can be cleaned with plain old carb cleaner, but don't adjust the pintle end.

7. Be sure the PCV system is cleaned out (carb cleaner, hose from each valve cover).

8. Plugs and wires go a long way toward smooth operation.

9. There is an ignition amplifier that can get hot and stop working.

10. If can't localize tap, with yard stick between your ear and valve cover, etc.; youi can try removing plug wires one at a time. If no spark in that cylinder it can make change in noise (connecting rod, etc.).

11. Shop manuals are called the RAVE, free download below.

 

Hey Savannah Buzz, thanks a bunch for the suggestions.
1. Being fresh out of the shop I am still running pure water in case we have to open the system again. Would you consider 212 to be an extra hot running temp? Whats normal in 85 degree weather?
2. Rodding the radiator is probably my next move.
3. Fan clutch seems to check ok.
4. Do you know what other thermostats may work in this car?
9. What would be an indication of a failing amplifier? Can I test it?
10. I'll try the unplugging wires routine to see if tap changes.
11. I've got the Rave manual, not terribly user friendly, but the info is certainly there! Thanks!

 

I run in the 180's in 90 -100F temps. On the road. With AC on. You can easily buy a 160 or 180 or 190-195 stat, same size as many old Chevy and Fords.

212 is warm, and the point where electric fan would switch on to help in slow traffic with AC on. Would want that to be below there on highway.

When the amp gets hot it quits, so no spark.

20W50 oil could help. Don't run 10W30, too thin.

 

Hey, thanks a bunch from Costa Rica. I'll be a few days putting the advice to use, things happen slow down here. Will report back later, Bill

 

I'm using email for this, I can't seem to figure the forum out. I noticed after the last engine build (there were 3 before the mechanic actually learned the engine) that the position of the vacuum advance unit was about 30 degrees counter-clockwise from it's original position. Mechanic says don't worry. I notice that the engine does not want to start if I retard (clockwise, I hope) the timing. Don't have a light. If I advance the timing (CCW, I think) to where the engine will readily start, the engine seems to ping on a long uphill grade and the engine gets hot (I don't know how hot, no movement from the 9 o'clock position, 110C, on the gauge). Could the incorrect position of the distributor be a factor here. (Seems at least one tooth off, maybe more) Could heavy spark knock (I thought at first I was hearing lifters, but was able to eliminate it by turning dist. CW a bit) cause an engine to overheat or at least get hotter than normal. As mentioned before, the engine has a history of overheating (had to rectify heads and block), and is very difficult to start when hot. (suspect coolant temp sensor, comp displays code 14). The car has 129k showing on the odo and is new to me two months ago. I swapped a '76 Series III even for it. Down here the Disco is worth 9k! BTW, I spent many years in Columbia, just up the road from you. Did many road trips to Savannah! Thanks for taking a look at this, I appreciate the help. When vacation time comes, come on down, I've got a guest house on the ranch available for you at no charge. Spend a few days, it's in the mountains. Later, Bill

 

Do you by any chance have a recommendation for plug wires and plugs, 3.9. Local parts house has Lucas wires and Champion plugs, RN12YO. Any good?

PS After running engine just long enough to introduce hot water into the radiator, I switched off and felt the engine side surface of the radiator. Hot on upper one third and barely warm on the lower two thirds. Repeated with same results until it got to hot to touch. Radiator went to the shop today.

 

Plain old Champion coppers. 7mm or 8mm silicone wires if you can get them. Old wires or lower quality wires can crack from the underhood heat, will look like spark show in total darkness. New wires that fit are better than old wires. So eventually you may need to change them again.