craigbau

Member
In a bit of an urgent pickle here, will come back and do a proper intro later. I have just replaced the head gasket on my 300tdi Defender and made an incredibly stupid mistake. I used the correct elring gasket and carefully followed all the directions to go through the 4 phases of tightening the bolts...... and then went to bolt up the air cleaner bracket that 2 of the head studs go through! Just rushing things i guess.

So now having researched the importance of carefully taking down the tension bit by bit, I hope i don't have to pull it back off again effectively and get another gasket! Given the the central bolts that have that extra 20 degrees turn are tight, do you think i can just pull out these 2 bolts and put them back and tension it all up or do i risk warpage of the head? do i progressively go through and loosen all bolts but not too much, say just 20 ftlb, pull out those 2 and go back over it again, or are all the crush parts of the gasket now done and it wont seal right?

If it matters, the engine has no fluids in it yet and hasn't run yet, only turned over by hand to do tappets.

Would greatly appreciate any help. And this is australian delivered car if that makes any difference to the air cleaner it has.
 
From the time I saw the removal of two bolts comment I knew where you went wrong :D

Since the gasket is new, you should not have a problem backing off ALL of the the studs and re torquing. On the BMW engines we built for boosting and even NA ones, we add a slight bit more torque. You might not warp the head but might not get a perfect seal from the two you will be removing.

I have not rebuilt a 300tdi engine as yet but soon will. I will use the thickest MLS gasket with the copper spray gasket binder intended for building high performance engines.

Did you use new head bolts by the way? The 300tdi and non stretch bolts so could be used again but I would say with age, change them.

You Guys in the UK and Europe in general get the parts so much cheaper, I would use as much new stuff as I could especially when it's as critical as head bolts.
You should be OK and it's good that you caught it now.

Cheers

.
 
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imo, you'll be fine taking those 2 out , sticking cleaner bracket on and retorquing. i did a year or so ago and it's not exploded yet.
 
imo, you'll be fine taking those 2 out , sticking cleaner bracket on and retorquing. i did a year or so ago and it's not exploded yet.

I agree Trax, he might get away with it but out of caution I would suggest he redo them all.

If the engine was used and the gasket had been already crushed and sealed over time, I would have risked removing the two only.

It would not require a lot of work to redo them all as opposed to risk of just doing the said two only.
If he does it all over again, it will be experience and a reminder for next time :D
 
If you touch them all you will see to replace head gasket, just remove the two and torque down afterwards, job will be good
 
having the air filter on the head bolts is bloody stupid imo. i bet loads of garages have had to redo those bolts
 
having the air filter on the head bolts is bloody stupid imo. i bet loads of garages have had to redo those bolts

I agree, I will either change the location on mine when I will install the temporary engine, or I will get a K&N with a proper heat shield which will be relocated anyway.
 
Firstly thanks everyone for such prompt and comprehensive responses.

Working through the points made, the car has done just on 200k km so I took a punt that the head was unlikely to have been off too many times and so i reused the head bolts. And it is all a bit caught up in the situation of just trying to get the car home - it is about 250km SE from where i live in Adelaide on the inlaws farm. I had been doing work further south and then broke down only about 15km from the farm, so rather than explore more costly options of moving the car, my father inlaw just towed me back to the farm so i could explore the options and was heading to Adelaide that day anyway, so i caught a lift.

What happened was the plastic clip above the water pump that holds the heater hose broke, heater hose rubbed on the pulley and next thing i am overheated. I let it cool and had water on me but didn't realise about the hole until later. It started and ran perfectly but a few km down the road overheated again. Then i turned it over without that brass screw in place on top of thermostat and it belched water out. I don't even know if that is normal but it was enough for me to suspect the gasket and hence the tow. Since then someone suggested a few things to try apart from gasket, but at 200k i have heard suggestions it is not a bad practice to change it anyway.

Because i was pretty sure the overheating wasn't too bad or too long I decide to take a punt and change it and see what happens - only a $50 gasket, few other bits and a bit of time vs something like $300 to get it transported here to then deal with it. And there was a family get together this weekend we were attending anyway at the farm - long weekend public holiday for the Queen's Birthday - I know when i worked in the UK (Worcestershire Wildlife Trust) my colleagues found that humorous! So my kids and cousins played, Wife caught up with family and i was perched up on the defender working, that the odd spectator that visited the shed over the weekend seemed to find very funny!

But back to the bolt subject, I can see all the points that have been made, I can see logic in all of it. Some more info, i checked the head with a straight edge and was pretty good but not perfect and combined with a bit of corrosion where it meets those triangular water holes - well in a perfect world i would have had it faced but that would have involved another 500km driving. I also noticed a bit of wear in those brass cam follower parts, bit of scoring on no.4 cylinder and noticed while a standard bore piston still, the brand was different for that one - so no doubt a past dodgy repair.

But what started as an experiment with this Defender (see my intro post i will do) I am a total convert now and it is perfect for my needs. So if i can get another year or so out of this engine that would be great and the gearbox, and then I will fully rebuild both. Long story but i have a very rusty 200tdi that i am 'derusting' and will sell eventually but will use that while i am rebuilding the 300tdi - bore, oversize pistons, new head studs and new head i would think - and one of those temperature alarms!

So, given that long winded background and all the info, i think i will take a punt and just do the two, save me redoing all the valves, but will check - but mainly i am thinking that someone has done it and been ok. If it all goes wrong, if the head is not straight enough etc etc, then it can all still go on a truck back to Adelaide and bring the rebuild on sooner. I can see the point to slacken all because the crushable parts of the gasket have not perhaps settled properly yet and letting it go disproportionately could crush different bits. But i am thinking of all those bonding bits on the elring gasket that i scraped off the head and block and i imagine that is not ideal for that to lose contact and more likely if i back it all off. If i was about to head off through the Simpson Desert then I would pull it off, get a new gasket and start again.

I'm thinking I might see if i can pull one bolt, put it back through one hole in the bracket, put a degree of tension on it and then see if i can swing in to put the last bolt through while it has some tension back on it - just a thought so it doesn't lose all the tension at once. I had to come back to Adelaide without the car last night, but will be back down again soon and managed to break the dipstick tube and that would be good to get a new one of them. Will give the air cleaner thing a bit of thought to. I found it unusual to have that bracket under head studs and also the water pipe under exhaust manifold nuts. Part of even pressure and getting tension even i always thought had something to to with friction against the nut or bolt face and having different materials, steel and alloy and cast - but what do i know! Obviously isnt a big deal since these cars have done billion of miles.

Anyway, thanks again. Will report back when i try to start it.
 
warped head and overheated twice due to lack of water..on a 300.. gl with just a headgasket change:)
 
I have a new question but I think i will put that in a new thread - but realise i didn't report back which is a bit rude given all the great help. It still took me some time to get back down to do the car (some 350km from home), but i removed the 2 bolts and put cleaner back and have done a few thousand kms now with faultless performance and a very steady needle despite towing cars etc at 100km/h. As i said it was an experiment where changing a $50 gasket is a lot cheaper to try than $300 transport. But trax's comment may still have some weight because a few days ago i fitted one of those water level sensors that go in top of the radiator. Although the car has not been losing fluid, it would appear a small amount of air is getting in the system somehow so perhaps there is a minor leak still in the headgasket, just waiting to get bigger! I guess it could be a pinprick hole in a hose that i have heard of, but then i would expect fluid loss and then when cooling drawing air - my thinking that compression blowing it in without it coming out. Yesterday i drove about 200km at 100km/h towing a big australian holden ute with all sorts of heavy crap in it (welders etc) (favour for a cousin!) and it performed perfectly, but each time i stopped and restarted that alarm would be on for several minutes - then quiet and not come back again - and temp guage always exactly in the middle with maybe a bit higher when pulling hard on hills and back in gears. I only put the alarm in to stop such an event happening again but without it I would be in ignorant bliss that everything was good! So sorry if i make anyone cringe but i am thinking of putting in a bottle of chemiweld. I know mates have used it to good effect and if it is a minor headgasket leak then it should seal it up. Ultimately the future for the car is for me to pull engine and gearbox, fit new head, bore it, etc and do the full rebuild - and then get hundreds of km of trouble free motoring hopefully. So might put in another thread in case it gets lost here but has anyone used chemiweld? the container says to take the top radiator hose off and pour it down the hose 'into the block' - for most cars though i think that is into the thermostat housing and the water is then headed to the radiator. As always, any advice appreciated. Towing my clubman to a motorkhana tomorrow about 200km.... but should be less than half the weight of the overloaded holden ute and should be a breeze!! And i must say the old landy never ceases to amaze people at its ability to tow big loads and good speed.... as long as the hills it goes up arent too big!
 
undoing and retightening any 2 outer bolts is perfectly fine without touching the rest , system will lose some coolant and gain some air, it just shouldnt be noticeable till you come to refill with bung on thermostat housing removed, which is why you should check level by removing bung ,monthly would seem apt to me, though more frequent cant hurt
 
When i realised i had forgotten the bracket and then removed and replaced the bolt, no fluid had been in the system. The bit that concerns me is that after the car had been topped up from the top above the thermostat, and ran fine and cool for a couple of hours continuous drive, and the water level alarm was silent - after sitting for a few minutes and then restarting, the alarm went off and stayed on for several minutes. Then checking there was some air in that top housing, and presumably in the top of the radiator from that alarm. Once running for a while it must force that air out i presume when the alarm goes off. I'm not sure if i am explaining it well, but my concern is that if the car is running and running normal temp for a long time, and the header tank has correct level of water, how does air get in the system? I presume a small hole in the system, on cooling and contraction could suck some air in, but I have looked very closely and while under pressure you would think that would have some sort of leak that was visible also. That's what led me to the thought that perhaps there was some leakage from the headgasket ie. under levels of diesel compression, small amount of air gets pushed past into the cooling system and hence the chemiweld thought. If it wasn't for this alarm i would have no reason to suspect any problem though because it is behaving perfectly. Yesterday i was running late getting to a motorsport event towing a car trailer up steep hills on the freeway in adelaide, 120kmh at times and was a hot day and the car at most on the steepest hills was 3/4 way on the temp guage, regaining to middle on down hills, so I think everything is good...... but this alarm is driving me crazy and also I'm just trying to get the jump on a future problem.
 
dump the alarm, youll find most need topping up if you remove thermostat housing bung ,level in tank doesnt show how much air or coolant is in the system
 

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