When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I've been out of rotary ownership for ~10years. I used to have a 1999 FD back in Australia and have missed it, so finally found an FD to build. It arrived to me yesterday, shipped from North Carolina. It's a 1994 FD3S Touring in white, with two-tone interior (soon to be all black). It's had a rebuild ~1000miles ago, so just run in.
The truck driver had me meet him in a parking lot up the road, since he couldn't turn around in my area. Unloaded the car and it was already up to temp and had a CEL. I took a quick shakedown drive (6miles). The car then overheated and spewed coolant over my driveway when I got home (10min drive), i had run the AC on full blast to test it.... I contacted the seller and he has not had that experience previously. I contacted the driver and he admitted to unloading the car in Sparks, NV (30min up the road) and leaving it idling for ~30min. It was 100 degree day yesterday, would that explain the overheating shortly after? Or should I be worried about deeper issues?
I checked the CEL codes, #16 and #33. Would those come up if it got hot or sat idling for an excessively long time?
Obviously, I've reached out to the transport company and the seller....
If it overheated while idling (possible), and compromised a water seal, then its presurizing the coolant which explains the puking coolant into the overflow when you shut it off. start the car (cold) with filler neck cap off and see if it produces bubble. If it does, file a claim with the shipper.
Something else was likely bad or marginal already for that to have happened though.
With a fresh motor I think you will be OK unless the engine was really poorly built or something. Do you know who built the engine?
I see in the picture it's peeing coolant. Where did that coolant come from?
It's possible you have a leaky hose somewhere or it got hot enough that it boiled over at the overflow tank.
Things I would do -
- Make certain the coolant system is solid and leak-free. There are pumps you can rent at the parts store to pressurize the system and see if you have a leak somewhere. May have had a coolant hose that was re-used when the engine was put in that shouldn't have been. If you have any bad hoses, get a new one FROM MAZDA and use the OEM spring hose clamps. Don't use generic parts store hose and worm clamps unless you like having a bad day.
- Go ahead and get a new thermostat from Mazda. Possible someone put an aftermarket thermostat in, many of them just flat out suck and fail in record time. They don't cost much.
Makes filling the system up with no air a breeze. Fill the car up with 50/50 green Prestone antifreeze and distilled water. You can either buy the Prestone pre-mix 50/50 or save money and get 1 gallon of Prestone and 1 gallon of distilled water at the grocery store.
- Make sure both fans are running and working fine. They will both come on at the same time. If one isn't running something is wrong with it.
I think you'll be OK. If it overheated while idling or light cruising that's not as hard on the engine as if you were on a long road trip or on a track or something. Also the fact that the water seals are new is a big plus.
Take your time, step through things, you'll be OK.
Purchasing one of these from the other side of the country has burnt plenty of people locally in the past....wouldn't be too much different over there I'd expect. It's all only speculation that anyone can offer until you do the champagne test or look for a bad cap, any hose leak sources or a fluid overfill.
Just on obvious things, the seeming lack of a battery hold down and all the missing plugs on the plenum grille gives the impression there was a touch of slap dash involved in the past.
It was spewing out of AST cap and the thermostat cap. Both are radiator caps which I know is wrong. Have replaced both with new ones today and ordered the correct filler cap. I don’t see any signs of leaks other than that.
I'm no expert on this stuff, but wanted to add that Dale has a great thread from 10 or 12 years ago on how the fans work on an FD. I used it to help me fix a problem with my '93 a few weeks ago. I nearly overheated my car and discovered the fans were not kicking on based on temp. They came on at low speed when the AC was on, but without the AC running, nothing. I ended up replacing the 3 "KE10" relays under the hood (on the rack by the passenger-side strut mount) and that fixed my issue. Fans now kick on as the temp comes up, then kick up from low to medium speed if the AC is switched on or an electrical load (like the rear defroster) is added. The relays were about $40 each from Ray. Dale can correct me if I'm wrong, but my understanding is the 4th relay in that rack trips the fans based on the AC running. Since that was OK on my car I haven't yet replaced that one, which was about $150 from Ray. Good luck with this problem and I hope you enjoy your new ride!
That video looks like normal air burping out. I think you will be OK. Again, just go over everything in the steps I outlined above to make 100% sure you have a healthy cooling system.
Kevin at RR does good work, that motor will be solidly built. I know he also pressure tests all blocks after building to insure they are "coolant tight".
Having 2 radiator caps is fine. The "flat cap" is the one you have to be careful of, if it goes on the AST you will have a bad time. You do have an aftermarket AST that doesn't use stock radiator caps so you may have to figure out what cap that needs.
Filler neck surround in that initial pic looked as if stuff had been spraying out.
Didn't look entirely promising, have you had it fully up to operating temp with the funnel? A pressure test would be the final arbiter.
yeh the filler neck and AST cap were spewing out initially. I’ve ordered the proper cap for the filler from Atkins, and got a new 13psi cap for the AST. so any expansion should now come exclusively from the AST into the expansion tank.
that video was at operating temp.
im taking it in to a local shop on Monday to pressure test, get it on a lift and help me figure out if it’s getting over pressurized with combustion products… fingers crossed!
Took it in to local mechanic today to be sure… They did a test to see if there’s any hydrocarbons in the coolant, leak and pressure tested. All passed.
the only thing wrong appears to be the cap on AST is leaking. I couldn’t find what cap it is, so I just ordered the banzai AST delete kit. Also ordered a water temp gauge to keep a better eye on it from now on.
hopefully I can kill two birds and tap the thermostat hole that went to the AST for the temp sensor…..
thanks again all for help. Slightly rocky start to my ownership, but all’s well that ends well I guess
Half hour idling in 100 degree weather will cause heat sink that will last a very long time (relatively speaking). You are probably past worrying about that.
AST delete seems a bit drastic, when an AST upgrade would do. The AST is there for a reason.
But if Dale is OK with it then the air bubble risk must be dealt in some other way.
I think my car had/has at least two preexiting bungs on the "filler neck".
There's more than 1 way to do it, it's been covered in depth in the past but I'll give the nickel tour.
Easiest and most reliable is just to take one of the existing AST hoses and connect the nipple on the thermostat housing with the nipple on the radiator. They both have to be plugged in some fashion to delete the AST has a hose going from it to the thermostat housing and another hose going to the nipple on the radiator.
Most hardcore way is to pull the thermostat housing and radiator and cut the nipples off and weld shut.
In your case I'd go option 1. It's clean looking, dead reliable, and works. Do NOT try and use cheap vacuum caps or something - they will fail within a week.
08-16-21, 01:00 PM
