About a month ago some buddies got my car tuned by Steve Kan while I was out of the country. After I got back they told me that the primary turbo was on its way out and only making 4-5 psi when boosting. Since then I've kept out of boost and just drove casually.

3 weeks later I noticed some coolant overflowing from the coolant reservoir, after driving home from work. (30 mile drive on expressways, temp never got about 190F)

2 days after that. Drove to a friends house 20 min away. Same driving conditions. Noticed maybe a cup of coolant on the ground in the same location.

Drove it home. Popped the hood to let her cool down, again same conditions never about 190F. About 2 hours later started her up without much of a hesitation, but did have a rough idle. Cleared up after 10 seconds. Started to back out and saw white smoke coming from the exhaust. Popped the hood and saw white smoke coming from the turbo area as well. Shut her off and put her back in the garage. Wasn't running for more than 4 min.

Started to do some research. Assumed it was the turbos, but the more I read it started to point towards a coolant seal.

So the tests I did are:

Coolant system pressure test - left it for 20 min at 13psi. Didn't drop more than .5psi over the entire period.

Pulled leading and trailing plugs. Trailing plug was wet with coolant.

Cold start with rough idle and white smoke coming from the exhaust - not much of a test more of just an observation.

Last, champaign test that looked like the following.

So my question is, can it still be the turbo since the pressure test was good? or have I failed enough tests to definitively say its a coolant seal?

Other than a rebuild, is there anything else I should be doing while the engine is out? I plan on doing the reinforced oil pan, but other than that anything?

Thanks for reading!

 

Time for a rebuild. Coolant seal is done.

Matt

 

What's the mileage on the engine? FWIW, it seems a lot like my car when the coolant seals failed. During boost, huge plumes of white smoke would come out of my exhaust. It happened twice before I had to limp the car home and it decided not to want to start anymore.

 

When I bought it I was told he had a Mazda long block put into it under warranty back in the day. I have all the paper work for the car, but haven't gone through it. So the engine either has around 60k on it or if it never had a new engine put in it would be at 110k.

 

Ugh, that makes me nervous! My FD has 62k on it. Hoping my coolant seals remain resilient!

 

Coolant seal is gone bro. No other way for coolant to get on the spark plugs like that. I'd plan for a rebuild sooner than later as coolant sitting in the engine can cause corrosion. Most likely that motor was overheated at some point.

 

I might hold the record for coolant seals My 1993 touring had 41000 miles on it when the coolant seals gave way. I think it was the harsh North Dakota -40*C winter that took it out. I do believe I'm going to switch to Evans coolant with my new build for better lower temp protection

 

Coolant seals are shot, rebuild time

 

^Note this. Don't wait too long or you'll end up having to source an iron.

 

how long is too long?

 

No way to be certain IMO. It may have failed even before you noticed the symptoms. I'd just rebuild ASAP and NOT try to "get by" with any of the Stop-leak stuff. I empathize. I've been there.

 

No no. No stop leak crap. Glad I never had to deal with that Slime stuff for tires when I was in school.

 

This sucks buddy, but on the bright side this give you chance to build it right.

 

Too long is anything that is not ASAP. Once the combustion chamber has coolant in it and ample air to oxidize the iron you will quickly get build up of rust on the rotors and the irons. If you can't afford a rebuild right away you still want to get the motor disassembled so it can dry out.

 

Now I'll be doing my own research but does anyone have strong feelings, good or bad, about any particular engine builders?

 

For what its worth:

We have a few wrecks (as we used to bring the cars over from Japan in containers regularly) a red JDM 1993 car had the same symptoms you just showed us. It turned out to be a bad coolant seal, sorry.

As a side note, we were going to strip the car in question, so before we stripped it down, we added some of that "insta-weld" chemical head gasket repair stuff to the coolant to see what would happen to the car. Voila, the coolant in the rotor housings actually stopped and the car began to run absolutely fine again. in fact it ran fine around the shop for about 4 months til we did finally part it out. So that was an unexpected thing for us.

 

Also time for a single turbo upgrade.

 

sounds like your buddies drove the car to hard and overheated it

 

You can't drive it hard with primary turbo boosting only 3psi, I tried when we were troubleshooting the boost issue at the dyno

IIRC it was trailer to and back anyways.

 

It had also been sitting in a warehouse for years. So I'd like to think it was never over heated.

 

^You can speculate what caused the failure until bin laden swims ashore. Just sitting that long could have caused it, since coolant tends to go acidic with time. Even on the best cared-for FD, seems like they tend to fail around 100k or so. Regardless, good luck. Sounds like you've got a good group of owners in your area and some good shops in reasonable distance.

As for a good time to go single turbo....meh, good time to paint the car purple metal-flake too, if that's what you want.

 

Yes, I've been debating if I'm going single now or not. But I don't really want to be down for the entire season. First full season owning the car and I'm already missing out on events.