Steam from turbo
 

I've got a 1990 NA, 1.6 with a mega squirt turbo. It's my daughter's car. She calls me on the phone and says when she got home she noticed steam coming from under the hood. She opens it and says sees it's coming from the turbo.

I changed the oil a couple weeks ago and noticed nothing wrong with the oil. Last week I noticed it was running hot when I took it for a drive. The radiator was about three quarts low so I filled it with some 50/50. Now, four days later, it's steaming.

Could this be a blown head gasket leaking into the exhaust? Hopefully something simpler?

Is the turbo water cooled?

Yes, it's water cooled.

I'd check that first personally. Not sure if it's possible but maybe water is pushing passed the CHRA and burning up in the engine bay. I've had oil push do this before until I added a restrictor.

I would expect it to be a leaking coolant hose at the turbo.

I know it seems obvious, but have you taken a light and inspected around the turbo itself for any signs of leaks or anything? Could just be a small seal leaking and burning off on the turbo itself. Also, does the steaming have a smell?

I have not looked at it at all. This is my daughter's DD. She bought it with the turbo installed by the PO. She just texted me that it was steaming and I did a quick search on here for a "heads up" before looking at it when I go home for lunch. There was zero relevant hits for "steaming turbo".

I'm hoping it's also just a leaking hose or something that simple, but I know next to nothing about turbo chargers other than the principle behind how they work. Again, I just wanted to get an idea from others as a heads up. For instance, I did not know the inter-cooler was independent of the engine's cooling system.

there will be two water lines on the turbo, horizontal to the ground. They should be simply plumbed from the from water neck, through the turbo, and then out to the water pump inlet. Chances are one of the water lines on the turbo is leaking coolant slightly and is the source of the steam. You'll want to find out quickly, as this water IS dependent of the engine's cooling system.

If that is the case, do I just put more 50/50 in the hose to refill it, and then clamp it back in place?

That hose is connected to the rest of the car. Fix the hose leak and put the 50/50 in the radiator.

Got it. That makes even more sense then since I've noticed the coolant was low in the radiator last weekend.

Okay, thanks for the help. The clamp for one of the lines was very loose. I tightened it and added the proper amount of coolant to the overflow bottle. Radiator was still full.

Thanks again for the pointers.

As long as you have rubber lines and clamps, you'll always run the risk of coolant leaks in that area. I know every so often I have to take the ends of the water lines, trim them off and re-install them because of the heat in the area causing them to eventually leak. I need to spend the $$$ on some hard lines :(

+1 on the hard lines.
Still, you might want to look into that overheating last week.

It was running hot because it was low on coolant. I filled the radiator and over flow bottle and the temp gauge never hasn't gone above half way since. This leaking hose/clamp explains where the coolant went.

I have to applaud a 16 yr old girl for having the sense to look under the hood so she could show me exactly where the steam was coming from while it was still steaming.

You bought your 16 yr old daughter a turbo miata? Ooh boy...

No, my daughter bought a turbo miata for herself. She didn't even know it had a turbo. She just wanted a convertible and it was in her budget..

Gotta post up some pics of this thing.

The car, I mean the car. :naughty:

I hope one of you knows enough about turbo Miatas to keep the thing running. A properly running and tuned turbocharged Miata for sale is the exception, not the rule.

Lots of pics of it on this site but here's one just for you.

https://www.miataturbo.net/attachmen...ine=1371696203

I've turned more wrenches than most people period. But I've never had a turbo charged car. One thing that surprises me though is a turbo in a standard. Much harder to build up boost. I've got a lot of grand national buddies and they mention that a lot.

But at any rate, it's a nice car. It only has 25k original miles on it and it's a 1990. A doctor had it and died a while back. He took it to the track a few times a year and that was pretty much it. His wife held on to it for quite a while and finally put it up for sale and my daughter found it on the interwebs. It came with the software and all to tune it but I haven't messed with it really at all. It runs just fine and she's not going to be taking it to the track so unless it starts running rough I'll leave well enough alone on it.