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4JG2T Coolant Flush

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4JG2T Coolant Flush

Postby TimboTheKiwi » Tue Apr 11, 2017 10:39 am

Hi all - new here so hopefully I'm dong this right, have searched the forums but can only see topics relating to overheating issues.

I have just recently purchased a 96 Wizard 3.1D, it wasn't in the best of shape maintenance wise but seems to be a solid truck so going threw some of the maintenance items I think need attention.

The coolant in the truck seems to have been neglected and a bit (not a crazy amount) of rust seems to be around. What I am trying to figure out is what is the best procedure for flushing the coolant system?
I have the thermostat housing open and have dropped the rad bottom hose and quite a lot of fluid has come out. I found a reference to a side drain plug by the starter motor but there was a lot of stuff in the way and I couldn't be sure that I had the correct drain plug bolt, so didn't pursue that option.

Also, as I am not the most knowledgeable when it comes to these trucks, any advice on any further maintenance items would be awesome. I have changed the oil/filter, will look at the trans fluid/filter, brake fluid, whinny turbo but if there is something I am missing please let me know.

Any ideas/advise would be much appreciated - thanks in advance! :D
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Re: 4JG2T Coolant Flush

Postby geeves » Tue Apr 11, 2017 12:31 pm

You are on the right track. A hose with good pressure should flush the block fine from where you are. Try to run it through both ways. Most rust inside the block wont budge though and sometimes a chemical flush is better although rust in the block isnt a major concern. Bigger worry is the radiator. Treat this the same way. If the water backs up at all its best to take the radiator to a specialist to get rodded.
Whiney turbo could be a hard one. Some turbos whine all the time with nothing wrong. Watch out though for a whine just after you turn it off This is the death rattly of isuzu turbos. However it might run 2 years or more like this or fail next week. Ive heard many bad stories about the chinese copy turbos
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 4JG2T Coolant Flush

Postby TimboTheKiwi » Tue Apr 11, 2017 1:30 pm

Thanks Geeves - appreciate the helpful advice.

In regards to the turbo - you are spot on - it whines on shutdown only, sounds like a jet engine shutting down. I was going to get it reconditioned it some stage later on - but would you recommend on getting that sorted asap? My little knowledge on turbo's suggested it was the cap/cover on the exhaust side coming loose and messing up where the internal covers/bearings are - although I am probably way off.
TimboTheKiwi
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Re: 4JG2T Coolant Flush

Postby geeves » Tue Apr 11, 2017 2:29 pm

These turbos are not generally rebuild-able. The problem is the internal heat shield was too thin and gets holes in it which whistle on shut down. This allows hot gas at the bearing and seal which eventually fails. 9 out of 10 failures are the seal resulting in lots of smoke and the other one could be either bearing siezure resulting in massive loss of power or if you are unlucky bearing collapse which unbalances the turbo and can cause blades from the intake side to get into the engine.
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 4JG2T Coolant Flush

Postby TimboTheKiwi » Tue Apr 11, 2017 2:57 pm

Oh geeze that doesn't sound like something I am after. I will pull it off and have a look and fingers crossed I can do a rebuild, otherwise maybe second hand turbo will be in the cards.

Also going to investigate a intercooler option and perhaps a new oil cooler if you have any ideas there? And your right on about the radiator I think ill go get a good alloy one - the exterior of this one looks like its been through the wars. Well I'm picking your brain what do you recommend air filter wise?

Thanks geeves, all the help and knowledge the better :)
TimboTheKiwi
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Re: 4JG2T Coolant Flush

Postby geeves » Wed Apr 12, 2017 6:11 am

I would leave the turbo till it gets worse Intercooler and bighorn one is easy bolt in but other intercoolers can be fitted with a bit of work. Air filter Cheapest option is a pod filter but you need to modify the airbox slightly to fit it
Sanding your knuckles before starting work can help. That way you cant skin them
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geeves
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Re: 4JG2T Coolant Flush

Postby TimboTheKiwi » Thu Apr 13, 2017 8:56 am

Thanks mate I will do just that - I can't hear any noises when under load and no smoke so hopefully it is just the very start of the issue and I can get some use out of it for a while yet.
Going back to the coolant flush - is there a purge/bleed valve to remove air in the coolant system?
TimboTheKiwi
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