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Dead / Dying TD42
Posted: Sun May 08, 2005 9:27 pm
by Slug
Put my `89 GQ in for some work and the mechanic says "How long has this knock been happenin" ? Not real sure says I ..thinking it was a tappet that needed adjusting. Upshot is that he feels its an engine bearing but isnt 100% certain and advised me to get a second opinion just in case. He is also concerned about low oil pressure at idle. He cracked each injector line while I watched and we could hear a slight difference in the noise when No 2 was cracked off. On top of that my aircon compressor bearing failed (1500ks after a new one was fitted) and destroyed the clutch on its way out. Aircon bloke says he wouldnt be putting the compressor back in at all without replacing it and at least one of the hoses :(
The upshot is
A: New / Rebuilt engine at worst case plus injector pump, injectors and numerous other widgets.
B: New/Rebuilt compressor, new hose, reciever/dryer, regass etc etc.
C: Spend a few bucks on her to tidy it up on top of the above and still have an `89GQ at the end of it all.
OR
Trade the bloody thing in for a later model GU... in which case do I look for a decent TD42 Turbo and be done with it or are the 3lt Turbos worth a look also... A quick search revealed that some of the 3Lt`s had major engine problems as well. Car will do a lot of highway work and eventually tow a Tinny all over the NT as I move from post to post. I did have a quick look at a GU in Darwin but it turned out to be a 4.5lt petrol

and I cant imagine how thirsty that monster would be.
Anything else that I should be looking for or be aware when looking at a GU ?
Sad and expensive days indeed :(
Posted: Mon May 09, 2005 12:25 am
by Woop
A faulty injector will give a sound exactly the same as a main bearing with excessive clearance. Low oil pressure at idle is normal--should come up to about 1/2way on the guage at highway rpm's. Oil pressure senders are known to go faulty.
I recently completly re-built my '98 TD42 at 550,000km's--not because it was using oil but because i was worried about main bearings. After removing everything, the bearings had only just started to show signs of wear. Small end bearings were almost like new and bores were in very good contition consitering km's. In the end, i could have easily kept on driving it without any problems.
Have the injector nozzles replaced and make sure tappet clearances are correct. The TD42 will ,if looked after and oil changed at the recommended intervals, easily go to over 600,000km's reliably--probably more.
Nick
Posted: Mon May 09, 2005 4:52 am
by DieselBoy
I love these stories of TD42's doing insane K's and then still looking good inside.
Fingers crossed mine will do tha same!!!
Get your injectors replaced.
Its a very simple job to check you main and big end clearences.
Drop the sump and use plasti-gauge.
I did mine in an afternoon, also replaced the crank shaft thrust washers.
Maybe some one can tell us if they have replaced the mains with the crankshaft in place???
It can be done on some engines, i did it to my old Triumph TC2500.
Pete.
Posted: Mon May 09, 2005 1:25 pm
by Slug
Thanks Woop
Given the stories about the longevity of these engines I was suprised he suggested bearings or the engine at all. I guess any engine can be damaged by neglect but I am meticulous with oil changes and so on.
You have restored a little faith! Will run it down to another mech for a second opinion and take it from there.
Posted: Mon May 09, 2005 1:56 pm
by bogged
place in Qld are selling TD42's for $4000 in 4x4 trader if you are interested.
add $4000 for turbo and zaust, and $2000ish for intercooler, and a Chev is a much cheaper approach :(
Posted: Mon May 09, 2005 8:26 pm
by beretta
When my old man was buying his GU, there was a bloke trading his GQ in, it had done 800k's on original motor and the old man reckoned it was in great nick! So they'll go forever!
Posted: Mon May 09, 2005 11:27 pm
by GQ Toy
Sold my 96 TD 42 and bought 03 TD42 intercooled for about $3000 difference - just got to sort out wiring for the refit
Could not fit a turbo to my existing motor for that price difference
Posted: Thu May 12, 2005 7:53 pm
by Slug
Second opinion came up with the same diagnoses .... Mains bearing is the most likely suspect
After looking at prices on GU`s I think I will keep the GQ and spend the money on her.... Time for an exchange engine :(
Posted: Fri May 13, 2005 1:56 am
by Woop
How many Km's has the engine done? Using oil between changes. Did he remove the sump and check the bearings?
Nick
Posted: Fri May 13, 2005 7:12 am
by Slug
Done a mere 220 thou....Doesn't appear to be using any oil and I am meticulous with doing changes every 5K.
We haven't dropped the sump yet but will shortly... even then if a journal is out of round or the cranks marked we are about shagged by the sound of it.
Posted: Fri May 13, 2005 7:54 am
by adam.s
bogged wrote:place in Qld are selling TD42's for $4000 in 4x4 trader if you are interested.
add $4000 for turbo and zaust, and $2000ish for intercooler, and a Chev is a much cheaper approach :(
or you are dumb for paying $6000 for a turbo/intercooler.
That quote is rediculously expensive.
Posted: Fri May 13, 2005 8:15 am
by Slug
So far the quotes for an exchange long motor run about 4.5K which is somewhat better than I though.
Posted: Fri May 13, 2005 8:21 am
by mkpatrol
Why dont you spend the small amount on injectors first? You will have to anyway when you do the engine, hell of a lot cheaper than replacing the engine to find out it was an injector problem.
Worth a try first.
Posted: Fri May 13, 2005 12:02 pm
by bazzle
Normally a dripping or stuck injector. Swap two over and see if noise follows.
If it does, injectors it is.
Take the easy lower cost option 1st as suggested above.
Bazzle
Posted: Fri May 13, 2005 12:05 pm
by bazzle
Normally a dripping or stuck injector. Swap two over and see if noise follows.
If it does, injectors it is.
Take the easy lower cost option 1st as suggested above.
Bazzle
Posted: Fri May 13, 2005 6:54 pm
by Slug

Ughhh
The noise is a loud metallic "thunk thunk thunk" audible from 15 feet in front of the car. I ran the injector idea past the mech again and he cant see it given he cracked off each line and it didnt shut her up. Also doesn't explain lack of oil pressure :(
Posted: Sat May 14, 2005 2:43 am
by Woop
Take the sump off and remove main bearing caps to be certain. Lack of oil pressure could be faulty relief valve/regulator valve. Very suprised that it would do a bearing with that minute amount of km's if your as carefull with oil changes as you say so. Does your oil pressure lamp go out after engine started?
Nick
Posted: Sun May 15, 2005 2:14 pm
by Slug
Yup, light goes out a second or so after start up. We will drop the sump before we do anything drastic. Although those who have listened feel its a bearing.
Looking at prices on exchange engine and other options at present :(
Posted: Mon May 16, 2005 6:22 pm
by Mark2
Many TD's have a knock which sounds like a bad tappet. Mine has it and it goes away when it warms up.
Have had a few mechanics listen to it - all say its piston slap in one cylnder and nothing to worry about at all. At least that cylnder will never sieze... Mines done 485,000 km, still runs like a dream.
Mates dad's TD42 did 850,000 before he sold it, motor was never apart. His had the same noise as well.