300Tdi possible head gasket failure??

[Defendozer]

Hi all,

Just looking for some advice and opinions on what could be wrong with my 300Tdi.

Here are the symptoms:

#1 A very noticeable lacking of power, it has been tuned by Bruce Davies in Sydney and compered to when I bought the car it just doesn't have the same pulling power that it used to.. Not as much grunt up hills etc.

#2 Fuel economy has gone out the window, I was consistently getting at least 600kms from roughly $80 worth of diesel, now I struggle to get just over 400kms from the same amount.

#3 It is blowing noticeably more smoke then it used to.

#4 I am also having to top up the water level in the reservoir every few days or so.

Now, does this sound like a bad head gasket or something else? I'm really not to sure about this one so any ideas welcome. I want to get some advice before taking any drastic action;)

The car has done almost 400k just so you know. Oh and I started noticing these problems in the last month and a half or so.

Cheers, Remo

[87County]

Probably time to buy a new head, gasket & head bolts.....

But firstly why not whip the head off and take a look see?

[manic]

Head gaskets are known to go around 200 - 250k , so at 400k you are probably due a new gasket anyway. Considering your problems it would be worth taking the head off for inspection and new gasket. Sooner rather than later.

Then check your valve clearances and timing (change belt if due).

At least that's what I would do.

[slug_burner]

Until you said that you had to top up the cooling system I was thinking split turbo to intercooler hose. If you dont have any external coolant leaks then I'm afraid it sounds like a head gasket.

[Defendozer]

It did split a turbo hose a year or two ago, it has got silicon hoses on now though and they are all fine because I inspected them the other day. I also checked all coolant hoses/areas for leaks and couldn't find any. I'll double check though.

I can't really think of anything else that would be causing the poor performance, could be the injector pump or something but that doesn't explain the coolant issue.

No record came with the car about the head being done so that's a start, and yes the timing belt is due for a change so would work well to do it all at once.

I have been looking for options regarding a new head and I like the look of Turners Performance heads, has anyone put one of these on their 300Tdi? Are there any noticeable improvements? Is it really worth the money or should I just get a standard one?

Thanks

[manic]

Your current CH might still be straight without any cracks, would be much cheaper to just continue on with it. If its gone wonk then performance CH is the upgrade option. Turners are quick to deliver. I have a turner performance one on my 200tdi but didn't notice much difference to be honest.

[flagg]

Before you pull it apart it may be worth doing a compression check..

[2stroke]

I replaced my head (300Tdi) with a Turner's performance one, under 1 week for delivery, $1000 ish including gaskets and bolts. Only done as a 253000km precaution. I don't think it made a big difference either. Also the old head seemed fine and the gasket was not leaking. It is running great now but it also got a new turbo at the same time, goes slightly better but boosts to 15 instead of 17 psi.

[Defendozer]

The main reason I am thinking of going with a complete new head is that when my Dad got the head on his 300Tdi completely rebuilt 3-4 years ago it cost him close to $600 so I figure it would be worth it to spend a bit extra and get a performance head from Turners which I've liked the look of for a while.

Sure I don't have to replace it at all but I'm just thinking that given the amount of miles on the car and seeing as I will have it apart anyway I may as well go all out and do it all at once.
It may seem silly but that's the way I look at it.

What else should I replace while I have the head off? Are there any precautionary maintenance things made easier with the head gone?

[manic]

If you want to renew as much as possible top side then a new CH sorts out the valves. Get new push rods and valve caps. You could renew the rocker assembly. With the CH off you can replace the cam followers and inspect the top of your pistons and cylinder sidewalls for damage.

Get a new set of injector clamp studs and locking nuts. Also new bolts for the rocker assembly. I broke these very easily because they had been stressed too many times.

And of course new bolts for the CH.

[redrovertdi]

Remember that if you put a new head on it will still be running on a used bottom end, its very easy to drop the sump and replace the mains and big end shells at this time, if your bores are in good shape you could also re ring while the head is off[refresh not recondition], also when was your timing belt done[while your there?], not trying to create extra work for you but what im mentioning is very easy to do.

[wowscounty]

gday there almost bet its a cracked head when you take inlet and exhaust manifold of look for a green streak of coolant in the inlet port of number 3 piston from the front. hope this hasn't been sitting around for weeks in this condition cause you could bend the con rod on start up like mine did best of luck and replace it with the good head from the u.k oem i think about a grand for the kit:

[cewilson]

400k on it. I'd be looking at the injectors & pump just quietly.......

[87County]

The main reason I am thinking of going with a complete new head is that when my Dad got the head on his 300Tdi completely rebuilt 3-4 years ago it cost him close to $600 so I figure it would be worth it to spend a bit extra and get a performance head from Turners which I've liked the look of for a while.

Sure I don't have to replace it at all but I'm just thinking that given the amount of miles on the car and seeing as I will have it apart anyway I may as well go all out and do it all at once.
It may seem silly but that's the way I look at it.

What else should I replace while I have the head off? Are there any precautionary maintenance things made easier with the head gone?

We recently went through this exercise and purchased a standard Turners head (w/valves etc), Elring kit and new bolts - less than $AU900 incl freight, 3 days from the UK (I was pleasantly surprised).

the lady who took the order (a mrs Turner !) was very helpful & seemed quite knowlegeable.

We installed new fuel spillback hoses and the difficult to reach heater hoses at the same time & obviously used a new manifold gasket (your defer will have more room to work at the rear) - if you want to chat send a pm with your mob no.

(We learned some little tricks like the initial locating of the rear bolts, cleaning of the deck and limited decoking, clean the hummel valve and install a new o ring, oiling the CH bolts, the right order to assemble bits incl the thermostat housing to the head etc).

The kit comes with instructions as to the specific tightening procedure and a $20 angle gauge will help you - some say use the bolt flats as a 60° reference (which would be fine if you could see the boltheads while you're turning them - unfortunately the socket covers them up !).

there is a discussion here :

http://www.aulro.com/afvb/technical-chatter/174234-300-tdi-head-gasket.html

[keith73]

Hi
I just replaced my head after i found coolant in one of the air pots.
I didnt replace the rocker shaft or the push rods only the glow plugs and valves as it came with the head anyway and off course the head bolts.It seems to be running alot smoother and quieter then it did before and more power.
I also replaced the turbo but thats the reason i took the manifolds off in the first place.
keith

[Defendozer]

Remember that if you put a new head on it will still be running on a used bottom end, its very easy to drop the sump and replace the mains and big end shells at this time, if your bores are in good shape you could also re ring while the head is off[refresh not recondition], also when was your timing belt done[while your there?], not trying to create extra work for you but what im mentioning is very easy to do.
So what is involved in replacing the mains and big end shells? How hard is it and do you need any special tools or something?

And yes the timing belt is due for a change as well so another worthwhile thing to do at the same time.