I have posted on where the coolant lines went before. I have since bought a haynes manual to help along with the help from you guys i found out where they went thank you. Since then i have been making alot of changes to my car new manifold, turbo, injectors, FMIC, link, some more maintence, and im about 2 hours away in wrench turning to have this thing back together. I ran into a problem in the final hours of it being on jack stands, or so i thought hooked all the new lines up i got for my turbo, and went to go put the coolant line that went to the long silver water pipe behind the manifold (not sure of what its called) there was no nipple on it for the coolant line to go into. When i got the car i was informed by a friend who was helping me that i had no coolant lines, and i had a non turbo air intake manifold. i was wondering if there was anyway possible that i could have a no turbo water pipe, because i do not see where it hooks into anything.

I have never heard that. Please only post factual information that you can back up with personal knowledge or a link to somewhere that can prove it.

so is it a bad thing not having coolant lines though, if i was going to DD this car? I don't have a turbo timer. looks like it may be something i would have to have my friend help me with, cause it runs far behind the PS somewhere

In all honesty i think the reason they werent ran is because the guy was lazy, because i could go on, and on with a list of all kinds of things i found wrong with the car when i was pulling parts off. I'm very new to turning wrench only have been at it for about 2 months. after i lost enough money to mechanics who ha;f a$$ the jobs, and had to end up doing the jobs over.

EDIT: Welp, forget about that post then

Here are the differences between the 1g N/T and turbo water pipes pulled straight from the 1g service manual. The coolant feed to the turbo is on the t-stat housing and the return is to the water pipe, a turbo water pipe also has a provision to run coolant down to the OFH.

1g N/T water pipe


1g turbo water pipe

It is called the "water pipe" surprisingly, and yes, the NT ones don't have the nipple on them.

You'll be fine without coolant running to the turbo. Don't shut it off directly after you run it hard, and if you're paranoid, let it sit for a second or two before shutting down. If it bothers you, know that you can go without until you can find the pipe and fittings in a junkyard.

There is no coolant going to the intake manifold (you don't have to add "air" to it, we know what is going on) there is coolant going to the throttle body though. There is an inlet and outlet for the Fast Idle Air Valve, FIAV for short. It's an air valve that opens when it is cold out to keep the idle high, and the coolant water eventually heats it up and closes it.

Many people drive their cars every day with the FIAV and Idle Speed Controller, ISC, removed entirely from their throttle body. I found with both removed it makes the car a little tough to keep going until it is out of my 1/8th mile long driveway, then it stays running on it's own (but poorly) until it is about 1/4 mile away at the first stop sign, then it idles pretty smoothly from then on out. If you can live with that, you can ditch that bulky crap under your throttle body.

I was running the other turbo for about 500 miles with no coolant lines, and it seems in good condition. I just got this new turbo, and i have heard that these MHI turbos run hot. I just dont want to damage anything i appreciate all the help you guys have been offering, because honestly i dont know what to do. If the safer route is to just wait until i can get a new water pipe then thats what i want to do. just would like some more opinions on what to do. That post that gofer put up looks like it would be a easy in easy out kinda job.

I ran a MHI 16g without coolant lines for 6 months and had no noticeable side effects, of course it was turbo timed but that doesn't mean you can't leave your car running on your own. There is a lot of controversy about running coolant lines vs not when it comes to MHI turbos, its not advised but can still be done if you must.

I don't think finding the correct water pipe would be too hard so doing it the right way is probably a good idea.

I may be wrong, but i beleave they sell that plug for like the 35rs, and turbos that dont run as hot. like the MHI, but thats what i was told.

Alright well Gofer heres a question for you. Can i keep the lines hooked into the turbo, or should i just leave them off? They have holes for where the bolts go in, but if theres no coolant going into them then i dont need to plug them up right?

didnt see where you said doing it the right way would probly be a good idea . checked my local pull a parts they have a couple cars in my year up there. I'm going to try, and get one off of one of those.

gofer said:

Here are the differences between the 1g N/T and turbo water pipes pulled straight from the 1g service manual. The coolant feed to the turbo is on the t-stat housing and the return is to the water pipe, a turbo water pipe also has a provision to run coolant down to the OFH.

Click to expand...

Don't forget about the '90 turbo model that used an external oil cooler and ran no coolant to the oil filter housing. This is a makeshift diagram, for lack of a 1990 service manual but it shows the difference between the others:

Tigerhorns said:

Alright well Gofer heres a question for you. Can i keep the lines hooked into the turbo, or should i just leave them off? They have holes for where the bolts go in, but if theres no coolant going into them then i dont need to plug them up right?

didnt see where you said doing it the right way would probly be a good idea . checked my local pull a parts they have a couple cars in my year up there. I'm going to try, and get one off of one of those.

Click to expand...

If you don't run coolant to the turbo, you can leave the holes opened. Make sure the water pipe you pick up is from a 2.0L non-turbo car to ensure fitment.

I run the non turbo water crossover pipe. I find it easier to use than trying to plug the old lower port where the "U" pipe would go to the turbo, not to mention is more reliable this way. I am currently running a PTE 50 trim, but I ran an Evo III 16g @ 30lbs for over a year with no coolant, no issues whatsoever.

I just welded my hole shut on mine and ground it flat. You cant even tell it was ever there and it was free.

Question: could you use a n/t pipe and then just run the coolant drain from the turbo to the ofh?

motozachl said:

Question: could you use a n/t pipe and then just run the coolant drain from the turbo to the ofh?

Click to expand...

How would that work? The back side of the turbo's center cartridge has a little "j" pipe which has a hose that goes to the tstat housing. I suppose this would be the "feed". The front of the turbo is the only part that connects to the crossover pipe, with that "U" pipe that crosses under. The pipe that feeds to the filter housing is a separate pipe entirely that runs behind the turbo, which also gets connected to a rubber hose that slips onto a nipple at the tstat housing.

Does this make sense...

motozachl said:

Question: could you use a n/t pipe and then just run the coolant drain from the turbo to the ofh?

Click to expand...

The N/T 1g pipe does NOT have the provision going down to the OFH, so no.

Thought mine did Regardless would this diagram work?

You've got your flow backwards (the green arrows/coolant actually point/flow the other way).

Effectively what you are doing there is sending doubly-heated water to the oil filter housing to cool the oil: first heated from the engine block and heated again from the turbo. Water flows through the engine block and, on a 1G is fed to the turbo through the thermostat housing. On a 2G, the feed is directly off the engine block. What you are feeding to the turbo is water post-heat transfer from the engine block. You have to believe that is okay because that is how it was designed. But the oil filter housing/oil cooler doesn't normally see that doubly-heated water. On the level of simply connecting pipes together, yes, what you have drawn should work. On the level of oil and engine temperatures, it may not be a great idea or it may not matter at all. Just something to consider.

Well this kinda sucks i just bought those coolant lines ><. I guesse i will continue on with out them, but im still going to try, and find a new water pipe. Thank you for all the quick responses