Noticed a very tiny leak at the rear of the engine coming from the head gasket. It's not even enough to make a drip on the floor or overtake the engine pan; however, it is a very slow leak. Over the last 500 miles or so, it barely moved the line on the reservoir.

Question is, can I wait a while to tackle it while I focus on other projects (my Defender 300 TDI needs timing belt, etc.)

I have inline thermostat mod so I barely get over 180 and I don't drive a ton but they are mostly shorter cruise trips.

Thoughts?

Also, when it's done, other than switching to ARP studs, anything else I should update/upgrade while they are off and being done? (Already has new plugs, wires, coils, PCV mod, coolant hoses, inline thermostat, coolant flush, Throttle body heater re-route)

Thanks!

 

Wait and keep an eye on it. Going into winter will help this as ambient temps will be lower. I also would not switch to arp studs and just use the stretch bolts as they work just fine so long as you follow the torque pattern and directions..

 

Run your coolant bottle cap one full turn loose from full tight and it will leak even less. Won't build pressure in the cooling system, so no pressure to push coolant out.

 

Reasonable to think cam and lifters are worn out. Maybe rocker arms too. Oil pump and timing chain while you are in there, maybe gears. Crank and rod bearings, perhaps. Depends on how much driving you'll do (you already said not much), how much your budget is, and if you are striving for perfection...

 

Unless it has been run low on oil pressure for a long time this is unlikely. I have multiple trucks over 200k on the engines, one got 18mpg last week on a trip to NC. These engines are very durable if the oil was changed regularly and oil pressure was within factory specs. Not saying they never wear out, but I have yet to pull one apart that had low oil pressure due to worn bearings. Cracked pump, yes, walked cam bearing, yes, but not worn rod or crank bearings.

 

I'd just replace the head gasket. Unless you were having other issues w/ the motor, no need to rebuild the whole thing unless you need to or want to.

And no prob to drive it awhile with a slight leak. Watch coolant temps like a hawk with ultra gauge or similar.

 

It only has 79k miles and runs great with no engine noise or problems. When the timing cover was off, the oil pan came down and there was almost no oil build up in the pan. Oil changes have been consistent and with full synthetic.

Ultra gauge rarely shows anything over 181 degrees

 

get an ultra gauge to monitor the temps and make sure to have an inline thermostat with a 180 degree thermostat in it, and if it starts spiking over 215-220, then replace the HG. you can go tens of thousands of miles with the right kind of leak.keep the coolant topped off. check it before any trips and bring extra water/coolant just in case. lots of cases of people going 20K or more with a leak at the rear of the engine. FWIW, all the way at the back is the coolant jacket. If it isn't getting into the cylinder, I wouldn't rush.