Past week or so, I've noticed my heater is intermittent. Every few days or so, it would blow cold air for a few minutes and get warm again. This made me think the thermostat was going out, but I didn't have the time or the funds to get a proper OEM thermostat so I've been waiting until I get paid.

Last night I went to start up my car. It was a little difficult to start [which it is sometimes because of my still-faulty TPS], but started right up on the second crank. Add coolant light came right on and a few seconds later it started to smoke white, granted it was 35 again. It kept going until almost warm and smelled off. Kinda sweet and oily. Mine always smells like a weed-whacker though.

I think I may have popped a coolant seal, but after some tests I did this morning I'm a little confused. My first one began last night when I got home. Not much coolant had left the rad but some did so I topped it off. Before I did anything this morning I checked the oil and the coolant. Oil looked a little weird. A little light on the upper part of the stick but not in the oil on the bottom. Level was fine. Coolant sank a little. I pulled the EGI fuse, cranked her over a few times and checked the plugs. I found mostly brownish residue but some of it was light. I did apply anti-seize to the threads, but I wiped a little greyish-tan residue from the electrodes of each. None were wet at all. I cleaned the gunk off them and put them back in.

I left the rad cap off and started it. It fired right off and there was no smoke but a little blue puff. The coolant stayed still for a minute then very slowly started to rise and dribble a little bit. I replaced the cap to see if it would build some pressure and it did, but I saw a bubble. I took the cap off the overfill and it bubbled a few times while I was watching it too. I'm going to borrow a pressure tester here in a second but that may prove inconclusive as I think I have a little hole in my rad too.

Daily beatings have taken its toll already but I'm glad my first build lasted 14k mi. Does it sound like a classic case of a bad coolant seal? If it is bad, I'm sure I have some options on seal kits based on internal damage. My S4 NA irons will be a pleasure to find but a bitch to port again, so I'm expecting it to be down for a while if the system won't hold decent pressure after a new thermostat, repaired/replaced rad and a good flush with distilled water.

I also realise the need to work quickly with coolant to keep things from rusting. Is it better to soak the parts in an oil after cleaning for storage, leave them dry, or like a fogging oil before sealing them up?

 

i would recommend doing a pressure test on the engine while it is cold.

let it sit overnight and then apply 13psi to the system and let it sit for 15 minutes. remove the EGI fuse and crank the engine for 3 seconds. remove the plugs and check them again for coolant.

and if the irons aren't worn out the seal walls can be repaired. i patch them for $75 per break, haven't had one fail yet. though you could probably get a replacement iron for about the same, just would have to re-port it.

 

Thanks, Ben. I'm gonna go get one now. My port is a semi-custom template. Would you be willing to do it if I sent you the template and an iron if that's what I need to do?

I'm assuming since no comments on anything else that it's pretty close to accurate?

 

yeah i can port match an iron if it comes to that.

no other answers since there's too many variables. it could be as simple as a faulty cap/overflow system and an air pocket that developed in the system.

if the plugs come out wet then you know the answer.

 

Thank you sir. Are you saying that I may possibly have an overflow problem and not a blown coolant seal? I have had an air bubble get in it before. Now, my overflow bottle stays way full but it doesn't rise any for the most part. Like I said, I did see a bubble or two when I checked it at idle.

I'll have to wait to do the test to get the correct adapter. I didn't check the box at the counter.

 

the engine can push the coolant out anytime, but to suck it back in, it needs a vacuum, so if there are any coolant leaks, it can't suck coolant back in = full bottle.

also possible the cap is bad/dirty. i have seen little bits of junk/dirt sit on the flange of the radiator, and make the cap not seal.

Ben's pressure test is step 2, after making sure the cap isn't full of crud

 

Coolant pressure test failed as I expected but it failed relatively quickly. The top seam of my rad does have a small pinhole in it, but after spinning it over and checking the plugs, the fronts were fine, leading plugs a little black and it had a silvery substance on them which I'm guessing was some antiseize from install. The rear is where I found the issue. There was coolant splashed onto the leading plug but the trailing was still somewhat clean.

I'm getting ready to drain the fluids and pull it apart. Should I pull the transmission too? How much of it should I pull off before I take it out? My concern is downtime here, as this is my daily. I'll need to be as efficient as possible in doing this. I feel I caught it before any major damage occurred, but I won't know that for sure until it's apart.

Ben, I'm tracking down templates for you in case I lost a piece of the seal groove.

j9fd3s, The cap didn't look great either. An old Casite in all Japanese must be a pretty old cap.

 

i usually install a murray 16psi cap that is sometimes listed for the FD3S, which helps prevent the system from purging unecessarily. they only last about 2 years but it's the best alternative to an OEM cap, can be found locally and cost about $8.

sorry to hear about the coolant in the rear chamber. my personal preference is to leave the transmission in the car along with the engine harness but everyone has their own ideal way of doing the job. i just find removing the transmission is a huge pain in the ***.

 

I can still use my pump plan for doing transmission fluid then. I don't know how I should remove the power steering pulley to remove the bracket. All I did was put the pieces together last time before the engine was put in, doing the work in a shop with all the old Mazda tools on hand which won't be able to happen this time.

 

i put the car in gear, and then loosen the p/s pulley, and then remove the belt.

 

I pondered whether this would work. I'll give it a shot. Thanks, j9! Will the pulley slide right off or is it pressed onto the pump and I need a puller like usual?

 

When I tried that, even with the car completely on the ground it still let the engine spin back against 1st gear for a second, and when it finally decided to catch, all that spun was the ps pulley under the belt. There has to be a better way to do this.

Aren't the only 4 bolts holding that bracket on, bolting up the AC compressor as well?

 

whack the end of the wrench with a hammer, or tighten the belt more so that the pulley can't freewheel.

 

I got it. The engine should come off soon, but I have some questions before I get the hoist out.
Mainly, I want to know about the clutch. I have seen some threads that specify that removing the pressure plate bolts with the tranny backed off some is a good idea. This sounds like a HORRIBLE idea to be honest, and I wondered if I'm going to get hung up on the throw-out bearing if I just loosen the bolts and start pulling it. With other cars, I typically have to stick a big flathead screwdriver in there so I can actually release it. I wanna know this while I've got the slave still on.

 

you don't have to do any of that, just unbolt the bellhousing and pull the engine off the transmission.

 

Good stuff. I have basically just mounts, oil cooler lines and tranny bolts to go, but how do I get the harness all out? I'm not trying to pull the manifolds off first unless I have to to get the harness out of the way.

 

if you don't want to disassemble the upper manifold then just unplug the harness from the ECU. i prefer to take the upper off in the car, but time is money for me so 30 minutes spent removing the ECU harness with the engine is lost effort for me.

i just find it also makes getting the bellhousing bolts on and off much easier also.

 

VDI section too or just the plenum?

 

upper and mid section on both s4 and s5. there's nothing to the mid section that keeps it from removing it along with the upper.

 

on an S5 its much less work to remove the upper and middle in 1 piece, which is nice because just removing the upper gets you nowhere.

 

I had to separate the two anyway so I can replace my fried TPS. It's only held on by the phillips underneath and that bitch is on there pretty good. I took the dynamic section off yesterday so I could get this screw out. The added leverage hasn't even helped me yet. Half a PB can and some blisters later, it's still not free. Probably the original TPS.

Okay next question. Soon it will be time to order a seal kit. I am thinking Atkins' Overhaul kit A, as it has all the coolant seals, gaskets, etc that I will need for everything, but also corner seal plugs and springs, side seal springs, and apex springs. I'm fairly certain that after only 14k mi I haven't done much damage to the seals or anything, as I very promptly put the car out of service when I saw it make some smoke, so I have considered reusing them. Especially since I don't have 1200 to shell out for a speedy rebuild with all new seals and everything. I know this is based also on internal conditions and may be foolish. This is why I'm looking for insight. This is only my second build, but my first on my own [The front cover is going to be fun]. My question is, what all am I going to have to mix and match since I have S4 NA irons and FD rotors and housings, but then all ancillary parts are S5?

 

would be good to know the compression before tearing it apart, if it's 100ish or higher then reusing the seals should net the same results. if it was borderline 85-ish then check the housings and seals while it is apart and then make a decision on what to replace. if it never gives you any starting issues and has decent response taking off from a complete stop then it is probably fine.

when replacing the TPS just leave that bottom screw out, it isn't needed.

 

Yeah that was the plan for the tps. I mean It's got two screw holes on the front. M6 x 1?

I never even burned oil really. I would get a little blue puff on startup, but I've never had a problem starting it before my tps started to go south, and as long as I launched from 4k+ I always got a nice jump from the line. I'll compression test anyway.

 

I want to add too that I'm most of the way through teardown. Almost got the engine out between working so much. What's the best way to compression test it at this stage? Can I do just the block with no fluids in it?

 

you can but you would need a bellhousing or transmission on the engine to attach a starter to it.