Does my Td5 have a blown headgasket?

**strangy** · 29th October 2009, 10:57 AM

Hi Hendrik, the tutorials here are simply fantastic, between these and the RAVE CD or manual, you will certainly nail it in a week. I was surprised how fast and easy this job has been. I started at 0900 and by 1300 had the whole lot off and stripped ready for the machine shop and I took no shortcuts. If you have successfully done a head gasket before on any vehicle, you will have no more effort for this.

I'm expecting it back tomorrow, which gives me time to clean up the block, fit the new washers and o rings to the inectors and fit the EGT probe to the exh. manifold.

I was not going to have the injectors cleaned as the spray pattern on the piston crown is clean and uniform.
Having originaly being told the units could be cleaned, I am now told no one can test them and the only cleaning that can be done is from the outside and you could do that yourself with a soft brush.

I am expecting about $160 for the test and grind. I discussed the hardened / throwaway head. Ive been advised they have machined more than 60 Diesel Hardened Alloy Heads from Toyo, Mitsi, Isuzu and Landy, all without ramification. According to them the main reason manufacturers say throw away is, when the head cooks up badly the warpage is too great to machine out leaving sections too thin, futhermore when the head warps that badly cam journals are no longer parallel and then shafts break etc. Most Ally heads cant take much more than 10 thou.

Futhermore the distance between centres of the camshaft and crankshaft is reduced requiring the timing chain tensioner to take up more slack and since the chain is of specific dimensions correct timing may be unachievable. Which is also one of the reasons why vernier camshaft pullies are found on modified engines.

At least if it is beyond repair Turner Engineering are offering full reco for $2500 AUD ( im pretty sure this included valves) A bare Hi lux or Isuzu head is more than $3000.

Good luck with it.

**Hendrik** · 29th October 2009, 11:18 AM

Thanks Strangy
Are you going to fit steel dowels from LR, as I have heard things like fitting the wrong steel dowels could crack the head? Also did you get the valves grinded, as it might be something I will have to consider due to the amount of kms mine has done.
By the looks of things, there are not too many things to remove to actually take the head off, just have to take your time I guess and make sure things are well organised.

johnclv · 29th October 2009, 02:47 PM

Mine used to "gurgle" away all the time - Head gasket was about the only thing that did not fail on the POS

Anyway - I have a ( comprehesive )head kit and other goodies that I am wanting to sell as I no long have my POS.

PM if you are interested. I am about to put it all up for sale on ebay on the weekend

Cheers

**strangy** · 29th October 2009, 04:03 PM

Originally Posted by Hendrik

Thanks Strangy
Are you going to fit steel dowels from LR, as I have heard things like fitting the wrong steel dowels could crack the head? Also did you get the valves grinded, as it might be something I will have to consider due to the amount of kms mine has done.
By the looks of things, there are not too many things to remove to actually take the head off, just have to take your time I guess and make sure things are well organised.

Steel dowels, yes. IMO and from a design view, the dowels really are a location device to ensure the head is aligned correctly with the cylinders, gasket and block. The head is retained by the bolt clamping force, not the dowels. I feel my type of gasket failure is not based on the type of dowel , but due to either poor bolt quality or torque setting at the factory level. With bolts stretching and losing there tension over time/use. Of course with severe heating it doesnt matter what bolts/ torque you had.
LR steel dowels are reccomended by TRS and many others for all engines.
However, again IMO, steel dowels will assist the head to stay in place at the upper end of pressure and heat if the bolts have tendancy to lose tension and will reduce the amount of potential failures. If the head has expanded and moved enough for the steel dowels to cause cracking, then the head will be useless regardless.

Valves, no. 220km on mine. No signs of abnormal wear and doubt any issues will arise here. There are hone marks still in the bores!

**Psimpson7** · 29th October 2009, 04:13 PM

I used genuine LR steel dowels without issue.

**Hendrik** · 29th October 2009, 05:38 PM

Thanks for the detail Strangy, very helpful.
If thats the case, I will go genuine LR dowels, infact thinking about going genuine LR for everything.

**Shamo** · 29th October 2009, 06:41 PM

Originally Posted by Hendrik

Kind of looking forward to doing this, it will run so much better with a new head gasket. Will also fit a low coolant alarm when I'm done, so I can be warned when another hose busts.

Why don't you just watch you're temperature guage?

What's so good about going genuine? the label?

Shamo

**Psimpson7** · 29th October 2009, 06:48 PM

Because the gauge isnt a live reading as such. there are basically only 3 readings. cold/normal/hot and by the time it moves you have generally done the damage.

Non genuine parts can be fine, unfortunatley they can also be absoloute junk.... I know which one I would use!

**justinc** · 29th October 2009, 06:59 PM

Originally Posted by Psimpson7

Because the gauge isnt a live reading as such. there are basically only 3 readings. cold/normal/hot and by the time it moves you have generally done the damage.

Non genuine parts can be fine, unfortunatley they can also be absoloute junk.... I know which one I would use!

And genuine parts aren't all that costly, when you figure in the labour attached to the job. It's All I ever use doing these jobs, genuine LR or Elring for gaskets, and SPS for fasteners.

JC

**Hendrik** · 29th October 2009, 08:07 PM

Well the head will be coming off this weekend, or I will try to make a start at least and see how far I get. Been looking at Rave and Pete's write up, and know how I will go about it. Will post updates as I move along.

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