Question about 3.0TD Cylinder Head

[Adrian North]

Hi everyone,

I have a 1999 3.0TD Colorado which I bought a couple of months ago. Just before Christmas she overheated and sent a lot of water out of the overflow onto the inside of the bonnet. I took her into a garage and they found that the radiator was leaking badly. They have replaced the radiator but on a short trip after I got it back the overflow sent water out again even though she didn't overheat. I have read on here about this engines cylinder head issues so I feel that this is the cause.

However, this engine had a new cylinder head and gasket (both from Milners) last year (just out of warranty now but not when the problem occurred) and they are quite expensive so I was wondering, before I go the the expense of getting another head whether there was a definitive way of finding out if the hear/head gasket has gone without removing the head to see. The garage I used tried some or other dye test but that didn't show anything but they have said that the cooling system seems to be overpressuring slightly but I am too much of a mechanical numpty to understand what that means.

Thanks for any help or advice you can offer

Adrian

 

[BobMurphy]

I had the same experience after replacing the head on mine.

I used an 'AMC' head from Roughtrax and a 'Milners' gasket.

A few months later the 'over-pressurising' problems were back.

I replaced the head gasket with a Toyota one and this time I used a very thin layer of jointing compound above and below the gasket.

The motor has been fine since and I tow horses with it so it doesn't have a quiet life.

I suspect that, like mine, the face of the block may not be perfectly flat, allowing combustion pressure to get between the thin plates of the head gasket (typically three plates rivetted together).

I had some 'ballooning' of panels in the old gasket, showing that the pressure was getting between the plates.

Its a pain removing the head a second time, but cheaper than replacing it again.

I do the work myself so its just my time and parts. If you are going to a garage you could get them to remove the head and carefully inspect the gasket, if its showing signs of pressure between the plates - ballooning like this - just replace the gasket.

If the gasket looks OK it is possible to pressure-test the head before deciding to replace it.

Let us know how you get on.

Bob.

 

[Adrian North]

Bob,

Many thanks for the reply - that has a lot of useful information in it - I am going to the garage on Tuesday and will take your info along with me - Unfortunately if I even attempted to remove the head I would probably manage to cut my arm off or something Computer programming I can do but engine fixing I am deadly!

If I have any more questions would it be OK to contact you?

Adrian

 

[BobMurphy]

If I have any more questions would it be OK to contact you?

Adrian

Of course .

And, I was a Computer Programmer (briefly) before I moved on to Systems Analysis / Business Analysis / Project Management / Senior IT Management, looking after cheque & cash processing machines, power supplies & networks whilst running a Development Team .

So don't give up on the Engineering yet

Bob.

 

[BobMurphy]

I think the reason I (we) got problems after changing the head was that, when a motor overheats and the head gasket leaks, there can be some 'etching' of the block face.

Its not easy to spot here, but I was getting water leaking into No. 4 cylinder (the rear one) before I changed the head:

The new head gaskets have a black coating, that, I think is a form of joint sealer, but it doesn't seem to be adequate on a worn block.

In a perfect world, one would have the motor out, strip it down and get the block re-faced. however a small amount of jointing compound seems to work.

I cleaned the block very carefully before putting the new gasket in 'dry'. But it didn't last .

What do others do ???

( A small warning . . In the top right-hand corner of the picture, to the right of that 'spigot', is the oil feed to the camshaft. Don't, whatever you do, block that with jointing compound ).

Bob.

 

[Adrian North]

Bob,

Many thanks for this extra advice - I will talk to the mechanic tomorrow and take your pictures along

Adrian

 

[DaveWall]

My 2 pence worth is dont skimp and save on a cheap head gasket! Its a pain of a job and worth a genuine item - I learnt this the hard way with my previous vehicles - (Duck and put on tin hat) Landrovers....

I have obviously grown up since then

Dave

 

[Adrian North]

Apparently Toyota do 3 different thickness gaskets for this engine - Is there any reason not to use the thickest when replacing it?

Thanks

Adrian

 

[silvercruiser]

it depends if you have any skimmed of the head etc so thats why you have different options. and if you use the thickest gasket and do not need it you can lower the compression and power, to what extent i do not know it might be minimal but im sure oters will be along with a little more technical knowledge.


Joe

 

[Leslie]

Hi
Bob has given you good advice, you dont have any discolouring of the coolant or a milky film in the coolant do you ,
Was the overheating resolved , the other fault is the cooling pipe for the auto trans is cooled by the radiator , this fractures and the coolant is polluted by ATF hence the radiator and engine overheat .
I was just wondering as you had said the gas test showed no fault , for your year and may be mileage a new radiator and thermostat should be fitted .

ATB

 

[BobMurphy]

Apparently Toyota do 3 different thickness gaskets for this engine - Is there any reason not to use the thickest when replacing it?

According to the manual, one should measure the height of the pistons above the face of the block at T.D.C. and then select the appropriate gasket.

Both the motors I have replaced the heads on have had "three-hole" gaskets (= three metal plates rivetted together). I haven't seen any of the aftermarket suppliers advertising anything else.

The thickness is indicated by the number of holes punched in the corner, like this:

See what comes out when the head is removed and use the same thickness when replacing (but I suspect you'll find its a "Three-Hole" ).

I presume its possible to drill out the rivets and use one or two of the plates instead of all three. The rivets stick out the side of the head when the gasket is fitted so the thickness of the rivet isn't critical. It should be easy enough to re-rivet the gaskets if necessary (has to be absolutely clean though).


Bob.

 

[Adrian North]

Once again thanks for the help and advice - the radiator has been replaced just before Christmas so that is, hopefully, one thing out of the equation.

Adrian

 

[Adrian North]

Does anyone know or can anyone recommend a good mechanic near me (Reading, Berkshire) - I have looked in the garage/mechanics section of the forum and have been to the one local one mentioned there - would just like to get some more estimates for the work before I finally decide so as to placate SWMBO

Thanks

Adrian