Coolant routing issue, again.

[MrMazda92]

'93 GS, Millenia engine swap.

I posted about this last year, and it's still unresolved. I've seen the shop manual black and white photos, time and time again. They don't answer my question. I've removed the battery, battery tray, VAF + intake, and more from BOTH of my MX-3s to compare. There are not coolant lines in this location on my '92.





At this point I basically need a picture of an actual car, not a diagram, showing where these should connect. I have no other "open" coolant lines to connect them to.

This is the one thing keeping me from driving my '93 right now, so I'm pretty intent on solving it quickly.

[mikeinaus]

are those not the lines that goto the throttlebody? they could also possibly be for the egr... if you\ve got everything hooked up just connect them together to stop any leaks and be on your way.

[MrMazda92]

The TB hoses were not routed there when I bought the car... I've had no end of trouble with this. I worry about connecting them together because it's entirely possible that something will not have coolant flowing through it if I do so. I've definitely considered it, but I want to be sure. The "diagrams" showing the routing are a joke, it almost makes me want to pull the engine and do it outside the car.

[mikeinaus]

there small coolant lines. the only 2 items that i know of that use small coolant lines are the throttlebody and the egr. the millenia engine you have doesnt have the same egr as the mx3 (its in a completely different spot and isnt cooled AFAIK), therefore there would be nothing to hook them up to. there location also makes sense that they are for the egr or tb.

are your throttlebody coolant lines hooked up?

either way the fact that they are smaller lines, means that they shouldnt be immediately vital to anything. all engine cooling lines (or jackets) are internal and wouldnt be affected, heatercore has fatter lines and also shouldnt be affected. if they were originally for an egr (which makes the most sense at this point in time) you would want to just put a connector in to complete the circuit and stop a leak. throttlebody has a few different reasons: 1 its meant to heat up the intake on cold starts to prevent throttlebody icing 2. its also meant to minimise condensation which could lead to hydrolocking in an extremely unlikely situation and 3. its meant to decrease engine the warm up cycle in cold weather to reduce wear and tear.

[MrMazda92]

They definitely are small. The TB is hooked into the system. IIRC the EGR is cooled, but those lines are hooked up elsewhere.

I think I'm going to hook them together for now, and idle the car up to temp, then look for leaks elsewhere.
I'm grateful for your help Mike.

I'm planning to bypass the coolant in the TB on my '92, but hadn't planned to mess with it too much on this car. At this rate, I may be forced to mess with it down the road.

Thanks again

[Daninski]

There's a coolant line to and from the EGR,,Putz.

[MrMazda92]

It's hooked up elsewhere, unless that is wrong. :/

[mikeinaus]

id just keep the throttlebody heated if i were you. i highly doubt it would have much if any impact on air flowing threw at wide open throttle, and the benefit it has with heating the combustion chamber on warmup would reduce engine wear. i suppose if its a summer car it wouldnt have much impact, but id bet it would help quite a bit on cold mornings. similar to a stuck thermostat...

[MrMazda92]

Well MoonEggs stopped by on his way home from Coburg, and he took a peak under the hood with me. Turns out I was right, unfortunately. The coolant piping on this engine is unusual, so I'll be undoing everything and trying to make sense of it this coming week. Thankfully I have a few extra parts should I need them.