Mixing diesel and oil 4JX1

It sounds like you might have a leaky head gasket, I'm sorry to say. Since you're right about the few places where these 2 fluids can interact I'm pretty sure that that's your culprit.

Hi, how about re-calibrating your engine? Get a certified engine mechanic and have your car calibrated....

Where are you finding this? Diesel and water would normally only mix if water was getting into the fuel tank. Are you sure it is diesel? If you are finding it in the coolant reservoir it is more likely to be engine oil. This usually suggests a blown head gasket.

About the only way diesel can get in the oil is if it leaks past the injector into the piston and past the piston/rings into the oil.
New injectors/injector seals should be the fix.

I do not understand what you are asking here.

This is typical of o-ring "seals" in the injector systemof the 4JX1 engine losing seal quality which will mix oil and coolant together and return both into the fuel tank and radiator. Smell the radiator. Most likley will smell of diesel fuel and perhaps show oil if you dip a timber ice cream stick into the radiator. Often occurs after overheating (towing or low on coolant). Buy an electric "ratchet" pump on eBay if you are going to fix the injectors [1 0-ring] yourself (and the sleeves [2 o-rings] per cylinder. You need a sleeve removal tool also. Instructions are available on Australian 4WD forum. The pump is to pump out of the fuel tank before you start the job. Take the input fuel line and hook into the pump. A plastic tube of the right size onto the outlet side and energise the pump. Drain into a 2 litre container(s) until diesel shows up instead of water. Drain the coolant before starting the engine repairs as some coolant pipes are made with rubber component pipes and could deteriorate if left too long. You need a copy of the manual (free online - do a search). You need to tighten the oil rail and injectors to the routine given to ensure good sealing. New copper washers for the injector ends are essential for good sealing. Ive had good results from using old rings for sizing and replacing with Vitane o-rings from hydraulic supply dealers. Label clearly when purchasing. Do not use standard rubber as they are not temperature rated. O-ring on internal injector plunger is "ceramic" and is not feasible for normal repairers and is usually not required. .RichW

Get some BLUE DEVIL and follow the Directions. You have a Blown head Gasket or a Cracked Intake or Head.

you need to replacing Injector 'O; rings properly,
we had good experience with those problems.
if u need timing pictures & Injector 'O' ring pictures i can send u.
Edirisinghe Auto Engineering(Pvt)Ltd.
Sri Lanka.

If oil mixes in the combustion chamber, then you're up for an engine overhaul. Nozzle changes won't do.

my isuzu bighorn will not start after changing valve seals and head gasket and after setting timing it still will not start. do you have a solution.