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Engine stuff....

PostPosted: Sat, 23 May 2020 2:25 +0000
by muddyhilux2020
Hi all

Got a 2006 Hilux with a 2kd 102bhp non intercooled lump
It does have a toyota motorsport tuning box fitted (128bhp and 300nm)

However, having a few issues.....

Driving home the engine temperature suddenly started climbing and blew the expansion cap off, and chugging smoke from breather (as in steady stream)

I've had head off, cant see any cracks in pistons but also cant see any obvious damage to head gasket
Head is flat (checked it wasnt warped)

Spray pattern on all 4 injectors looks a little wide (originals at 145k miles)
I've had them tested and 2 came back as worn beyond spec

Now I'm a diesel mechanic by trade for many years and to be honest I'm a little confused!

If head gasket had gone, I can understand pressurising coolant, injectors leaking explains rough running etc but not really blowing expansion cap off due to pressure

And the blowby could be explained by cracked piston (wondering if its cracked on side through ring lands)

But, to have serious blowby, rough running and heavily pressurised coolant at same time seems unlikely and very concerning
It was borderline whether it was going to run away with itself!
Turbo is fine, no play and no oil leakage just to rule it out


In all the years of working on diesels (ranging from small car engines through to truck and agricultural engines, I've never experienced a failure quite like it.....

Seen plenty of HG failures, injector failures, cracked pistons, thrown rods etc

But having symptoms of hg failure, injector failure, cracked piston/liner and oil consumption all at once (was running sweet and smooth less than 5 minutes before)

It's just a little mad, so thought would ask on here for thoughts, as it's the first 2kd engine I've ever had or worked on!

Re: Engine stuff....

PostPosted: Sat, 23 May 2020 5:58 +0000
by hiluxxury
Thats not good to hear. To my knowledge of the 1KDs, the headgasket is reliable.. I dont think I've seen a failure here or on other 1kd forums. But anything is possible.

*edit: found this... http://www.tlocuk.co.uk/forums/viewtopi ... df0e86377e

Re: Engine stuff....

PostPosted: Sat, 23 May 2020 6:54 +0000
by Gipsy
Probably most unlikely but worth a look, is there a crack in any of the cylinder walls through to the water jacket? Your symptoms sound like head gasket or cylinder head crack but cracked piston wouldn't blow the coolant and cause expansion cap to blow. Most unusual symptoms as you pointed out. Broken rings can give some of those symptoms but overheating?? Looks like a major job which probably requires a new mill.

Re: Engine stuff....

PostPosted: Sat, 23 May 2020 4:06 +0000
by muddyhilux2020
Mine is the 2kd 2.5 not the bigger 1kd 3.0, which I was told was a more reliable engine (less prone to cracking pistons)

I had a look at the cylinder walls but cant see any score Mark's or cracks, but if its microcracks, may not be visible....

It's a manual as well, as I had head of radiator failure on the 3.0 mixing with atf

More strangely (and more concerning!) Is there is no sign of oil mixing with water.....
Coolant does however smell a little as though combustion gasses have mixed, and the serious amount of pressure (it actually blew the cap clean off the expansion tank) suggests the system was exposed to combustion as no other way it would pressurise that high

Oil level actually looks to have increased as well which suggests diesel in oil, as its definitely not water.....


As I said, I've been a mechanic for many years, primarily diesel engines, and have never seen anything quite like this!
I do believe there were signs of metallic flakes in coolant as the whole engine bay got showered with the coolant, so wondering if its had radiator leak and had sealant in it

But, I inspected the head gasket again, and even opened up between layers and cant see ANY signs of combustion travelling away from cylinder etc
Usually you get tell tale soot Mark's or steam cleaned strips etc depending, there is nothing.....the head gasket looks pretty damn good
Head is fine, still perfectly flat, and no cracks etc, which suggests the fault is else where.....

Re: Engine stuff....

PostPosted: Sat, 23 May 2020 8:56 +0000
by dave g
Hi since you have the head off why don't you have it pressure tested and checked out. Had a head that look perfect once before I had it pressure tested the crack could be seen the dye shows through.

Re: Engine stuff....

PostPosted: Sat, 23 May 2020 10:40 +0000
by muddyhilux2020
Was going to but with lockdown cant get it done sadly!