94 DI - Pinging and gets hot under a load

[Big Ben]

Hi all, Drove up to the Sierra's Sunday and the engine was pinging (detonation) as a heavier load was applied going up the long grades. Finally at about 4,000' it was getting warm so I pulled over and let her cool off. Decided to head back home. Drives great on flat (even in 105 degree heat with the AC on), but with a load it pings and temp increases. The heads were reportedly done not long ago and look relatively new. At the last smog check it showed timing right on. I was running premium gas too. Did have the roof rack and kayak on the top but that should not contribute (much). Other than this it runs great.

My wife says if it can't go to the mountains, why do we have it? Ideas? - Thanks, Ben

 

[p m]

If the timing is right, the cause for detonation is running lean. Pump/filter ?

 

[terryjm1]

My understanding is at high elevation you shouldn’t even need premium fuel. I live at 8000 feet and 86 octane works just fine.

 

[Blueboy]

Hi all, Drove up to the Sierra's Sunday and the engine was pinging (detonation) as a heavier load was applied going up the long grades. Finally at about 4,000' it was getting warm so I pulled over and let her cool off. Decided to head back home. Drives great on flat (even in 105 degree heat with the AC on), but with a load it pings and temp increases. The heads were reportedly done not long ago and look relatively new. At the last smog check it showed timing right on. I was running premium gas too. Did have the roof rack and kayak on the top but that should not contribute (much). Other than this it runs great.

My wife says if it can't go to the mountains, why do we have it? Ideas? - Thanks, Ben

Peter M is right (usually is ) not getting fuel and then running lean. Forget the smog test and have someone actually use a timing light and check it. Check the fuel pressure. Also how old is the cooling system? Fan clutch, radiator, thermostat, etc.? When were the plugs / wires renewed? Cap / rotor?
Your D1 should easily handle the trip you described. Your wife is correct-it just needs figured out.

 

[Flyfish]

X2. Retard the timing a bit.

And it may be worth using a piston stop to determine if the the TDC timing marks on the balancer are correct so you know what the true timing is.

 

[Big Ben]

Thanks Guys, I did the hoses, thermostat and plugs. Will check the timing mark, timing and radiator. Pretty sure the radiator is old. Not used to injected land rovers or computers. like all crazy Land Rover junkies, this one needs work but i am going to pick up another one next week in AZ. Have an empty truck to haul stuff from AZ to Nor Cal if needed. Ben

 

[Flyfish]

If it wasn’t getting hot before, then its probably the timing. You probably don’t want more than 7° BTDC. Spec is probably 4-5° BTDC.

 

[p m]

If it wasn’t getting hot before, then its probably the timing. You probably don’t want more than 7° BTDC. Spec is probably 4-5° BTDC.

For a 95 RRC, it is 8 before. It runs very well with 9 on premium gas, without any pinging. As little as is the difference, at 6 degrees before it runs noticeably worse.

 

[Flyfish]

I believe 8° BTDC should be for the 4.2.

D1 & RRC SWB 3.9 is 5° BTDC. But to pm’s point, small adjustments make a big difference..

 

[p m]

I believe 8° BTDC should be for the 4.2. D1 & RRC SWB 3.9 is 5° BTDC. But to pm’s point, small adjustments make a big difference..

I'll check tomorrow

 

[Flyfish]

I'll check tomorrow

My 95 RRC SWB 3.9 is 5, +/-1. He wouldn’t have a 4.2.

 

[Blueboy]

My 95 RRC SWB 3.9 is 5, +/-1. He wouldn’t have a 4.2.

Same for the 3.9 in the D1: 5° BTDC +/- 1° for 9.35:1 compression, catalyst according to Engine Tuning Data in Workshop Manual.

 

[terryjm1]

While I wasn’t having pre-ignition issues (even with 86/87 octane) I was having overheating when driving on longer mountain grade increases. There was no overheating at all on flat land or idling.

Installing a new radiator completely solved the problem. Radiator had 155,000 miles.

 

[Blueboy]

While I wasn’t having pre-ignition issues (even with 86/87 octane) I was having overheating when driving on longer mountain grade increases. There was no overheating at all on flat land or idling.

Installing a new radiator completely solved the problem. Radiator had 155,000 miles.

Yep, same on my D1. While there changed out the thermostat, water pump, fan clutch, new hoses, and new coolant of course.

 

[p m]

My 95 RRC SWB 3.9 is 5, +/-1. He wouldn’t have a 4.2.

Ha.
I wonder if Land Rover just pulled the numbers out of thin air. Indeed 8 degrees is for 4.2; the workshop manual even lists different mechanical advance settings for 4.2 and 3.9.
Whatever it is, the sticker on my LWB says 8 - and the 3.9 based on 4.0 block I have likes 9 more than 6. But I only use premium gas.

 

[Blueboy]

Ha.
I wonder if Land Rover just pulled the numbers out of thin air. Indeed 8 degrees is for 4.2; the workshop manual even lists different mechanical advance settings for 4.2 and 3.9.
Whatever it is, the sticker on my LWB says 8 - and the 3.9 based on 4.0 block I have likes 9 more than 6. But I only use premium gas.

On my RPI 4.6 also run 8° and even with 93 octane get just a slight ping on some hills around here. ECR had it at 12° which worked great in Switzerland where pure 91 gas was available and even in the Alps ran great. As soon as it came back home had to retard back to 8°.