M.T.Pilot

Hello,

Short story
From my double cabin pick-up toyota hilux (1989, 4WD, manual) there is coolant leaking from a hole in the cylinder head under (not behind!) the cylinder head rear plate, there where the cylinder head sits on the motor block. How should I proceed in repairing this? (And what could cause a hole in the cylinder head?!).

Long story
I've got a double cabin pick-up toyota hilux (1989, 4WD, manual) to which, since recently, I had to add a bit of coolant on a weekly basis. I figured it was a minor leak from one of the hoses that was quite worn out. However, all of a sudden when standing still (but with the engine running), all of the coolant was streaming out of the engine.

I found out that it was coming from under (not behind!) the cylinder head rear plate. With my fingers I could feel a hole (!) in the cylinder head, there where it contacts with the motor block. I think there is supposed to be a gasket in between the cylinder head and the motor block, but the hole is so (relatively) big that this would not prevent the coolant water from streaming out of the engine.

Any idea how to solve this?

Thanks,


M.T.Pilot

brianh699

22re? If so the rear plate has it's own gasket http://personal.utulsa.edu/~nathan-b.../7cylinder.pdf

Dauphinc

I don't remember anything being under the rear plate and I just finished my rebuild. Double check and make sure one of your bolts didn't fall out of the plate. If that's not the case, get a lighted flexible mirror and use it to look in the back to see what's up and post some pics.

M.T.Pilot

Thanks for the link! My engines looks a bit different, e.g. the cylinder head rear plate is not the same. But it does have it's own gasket. And from the looks of it, someone has done some work on it in the past.. a liquid gasket has been used.

From what I could see, all 4 bolts were in place. I will try to get pictures (hopefully I can get my camera in between there). But the problem is not the rear plate, as far as I can determine. The hole is situated below the rear plate (not behind the rear plate). Basically at the bottom edge of the cylinder head (so essentially, it is not a hole, but because the cylinder head is placed on the motor block, effectively it is a hole). Maybe the wear also took place at the motor block side, I'm not sure, I have not been able to get a really good look.

I'm thinking maybe somehow the gasket between the cylinder head and the motor block wore off and somehow bit by bit this wearing on the edge of the cylinder head took place? I don't know. I think it is a pretty abnormal kind of wear, but there you go..I've seen the coolant stream out of there.

How should I go about repairing something like that?

I think the cylinder head rear plate could essentially be considered an EGR cooler plate, right? There is a "pipe-outlet" on it (don't know the proper word for it), with a rubber blocker on it (again, I'll try and make photo's). Maybe I could get longer cylinder head rear plate (homemade?) which then also covers the hole and put lot of liquid gasket between it and then use a couple of parker screws additionally to the 4 bolts that normally hold the cylinder head rear plate..don't know.. And I suppose the gasket between the cylinder head and the motor block needs to be replaced as well (can liquid gasket be used for that?).

Dauphinc

If its a leak that is the head gasket the proper way would
Be to remachine your head and replace the gasket. I don't know of anything else that could fix it properly besides that. Maybe it's something simple, just let us know what your pictures find bud.

M.T.Pilot

I do not have the car at my house (I towed it to the nearest friend, instead of having to go a long way on dirt roads to my house), but today I was there to take a better look and to take some pictures.

Here's an image:



The hole is there where you can see the rather bright green coolant. It is pretty wide and is due to wear/corrosion. I still don't know how it got there. The cylinder head rear plate seemed to have been leaking. Maybe the coolant stayed put on that little "ledge", right where the gasket is between the cylinder head and the engine block. The coolant might be a bit weak, I do not know about that. (Our water is very soft water, b.t.w.. We get it through reverse osmosis from sea water).

B.t.w. The engine is a four cylinder 4Y engine, not an 22R(E). (Probably similar to the 22R(E) in many respects, though?).

A friend of mine took a look and said what I feared he would say (and what you are saying): the aluminum cylinder head needs to come off. It can be repaired by welding and remachining. But first he's going to look for a second hand replacement. Of course the head gaskets need to be replaced as well.

Dauphinc

Wow..it looks like a coolant passage rotted out completely through the head!! That's insane man

Kiroshu

Wow a 4Y they are pretty rare to see.

They are a different family of engine and have a lot of differences compared to the 22r engine.

That corrosion related damage/hole does not look very attractive... >_<

That sealing job to that rear plate does look a bit low quality... >_<

Sure that coolant is leaking from that hole or not just running down from the leaking plate and kinda of sitting on that ledge that you say is a hole...?

Kind of difficult to interpret the picture .

Corrosion is not your friend... >_< seems to be a culprit of a lot of damage here.

If its not the rear plate leaking and indeed that damage/hole... you might be looking at some extensive engine repairs.

You might get by with cleaning and drying the area and applying some J&B Weld as a temporary repair.

Cyberman

If you give up on fixing it, let me know. I'll take it off your hands.

M.T.Pilot

Thanks for the reply, guys! Indeed, the coolant passage rotted out completely through the head (and was busy working its way towards the cylinder). I haven't got a picture of it. It will be welded and remachined, I think today (for $65). I bought a new head gasket, will have to buy a gasket for the manifold and new valve seals.

I need a new rear plate as well.

@Cyberman - I'm on a small island in the Caribbean, I think it will be pretty expensive shipping it to Dillsburg. But apart from that: it WILL ride again!

I'll keep you updated.

Cyberman

I'm sure I can fabricate some kind of raft to get it here

M.T.Pilot

@cyberman:

The pickup truck is driving again. Welded and remachined head, new head gasket, new manifold gaskets, new valve seals, another rear plate. I'm happy about that.

But I am not happy about the rattling sound it now makes. It seems to come from behind the dashboard, but I'm not sure. It is there when I push the gas pedal. If I do this and at the same time push in the clutch pedal, the sound stops. Also, it is not always at the same volume and the way it sounds can vary as well.