Coolant Loss/Rebuild Thoughts

[allstaruk]

Hi

My cooland buzzer has started going off on a regular basis, the car is losing apprx 400ml of cooland every 2 days of normal driving prob 30 miles a day at most. The buzzer only seems to come on when the car has been left over night, i have never driven anywhere when the buzzer has been on it has always come on just after I started the car and I have alway shut it off instantly and topped up the water.

With the water topped up the car drives fine, I have looked and can\'t see any leaks anywhere so could this be water seal failure, if so what are the symotoms and risks of drving it.

Pt 2

If this is the dreaded re-build time, what are my options, I have all the tools and an engine hoist, I can\'t afford to pay someone to fully rebuild it so I will have a go at doing it myself, I have enough friend and family and hopefully everyone on hear to give advice if needs be during this process.

Am I correct in thinking that if the engine is still running at the moment then it might be best to stop driving it and re-build, would this allow for more re- useable parts, I\'d imaging I\'d be more likely to be able to re-use the rotor housings.

If I am to re-build it can anyone suggest a good re-build kit and apprx what sort of cost I\'d be looking at? I intend of keeping the car fairly standard so I won\'t be needed any porting. Also after looking about I have seen most manufactures offer basic and masted re-build kits what is the major diffrence and what else would i need to buy thats not included in the re-build kit.

Any advice would be greatly appreciated.

Thanks

Alan

[ds2000]

You are correct with your thinking in PT2.

About PT1. Get the car up to normal temperature and keep it running, or get someone to hold the revs at about 2,000rpm.

Keep it there for a good few minutes (3 or 4) and have a look under it.  

Have a look to see if there are any obvious leaks.

Chances are you may have the issue I had which was worn turbo lines, fingers crossed its that

[allstaruk]

Cool I will have another look but I can\'t see and leaks from anywhere, also the car has done apprx 75k on the original engine.

[Grizzly]

The main Symptom of a bad water seal is poor starting, i found with mine its worse if you go on a run so its Hot then leave it over night (it strugles to start). A pal of mine has also told me he had a water seal go and if he let it cool down for a few hours then took the plugs out and turned the engine over slowly by hand (not on the starter) he could see small amounts of fluid running out of the Plug holes.

Something too try if you haven\'t already. Try getting the car warm (Just so the rad is at operating temp) then turn it all off so everything is dead (maybe disconect the battery??) and listen carfully for the Hissing noise of a leak, see if you can hear anything around the Rad,AST,water Pump area and Under the dash.

If it is the worsed case you can get overhall kits from here, http://www.rotaryresources.com, I\'d say for Plates etc contact your Local Rx7 Man (there are some of the best at the Top of the page ^)

[allstaruk]

It has no problem starting at the moment, when turn it off from hot it I can hear water bubbling from around the turbo area, although no obvious leak, it has always done this though.

Is there a definate way to tell if it is water seal failiure would a pressure test on the cooland system tell me?

Al

[kbareham]

Alan
I was thinking it was rebuild time a while back due to coolant loss. Mine started easily, and didn\'t blow out water when started from cold with the filler cap off. It turned out to be several small leaks in the cooling system - throttle body pipes, AST pipes and cap, and turbo pipes. The leaks were small enough that I didn\'t see any signs of water escaping.

Now the system holds pressure properly when hot - the radiator pipes are very hard. Also it holds slight vacuum for weeks after cooling if not used - it holds down the rubber seals on the caps. It didn\'t do either before I replaced the pipes.


Keith

[allstaruk]

Thats good to know so how do I know of I have this problem, is there a quick way to check to see if I have waterseal failure would a pressure test on the cooland system tell me this?

[Grizzly]

The main Symptom of a bad water seal is poor starting, i found with mine its worse if you go on a run so its Hot then leave it over night (it strugles to start). A pal of mine has also told me he had a water seal go and if he let it cool down for a few hours then took the plugs out and turned the engine over slowly by hand (not on the starter) he could see small amounts of fluid running out of the Plug holes.

I just spoke to the Guy who did this ^ and he said he turned the engine Bacwards too? Duno why and a don\'t know if it would make any diffrence but i\'ve not done it myself so??

I don\'t think there is a 100% sure fire test for the Coolant seal, As people have already said you can watch for Bubbles in the Coolant when its cold stuff like that but like and thing there is always more than one thing that can cause this? So to be Honist i\'d let a Pro engine Builder look at it if there is one close and give you his Opinion, mainly becouse they see this sort of thing all the Time and will tell you without much problem.

[Grizzly]

Thats good to know so how do I know of I have this problem, is there a quick way to check to see if I have waterseal failure would a pressure test on the cooland system tell me this?

Be careful Doing a water test where you apply Pressure to the System Stationary, I herd of a guy hydro icing his motor by forcing water into a rotor bath, so if you do it like this make sure the Plugs are out so you don\'t do any Damage

[petejp]

Ive had the same symptoms on my FD ie loss of water overnight after a run and warning light with add coolant the next day, I bought a new ast cap and "O" ring, after removing the 2 bolts and releasing the cap housing I noticed a hairline crack from one of the bolt holes to the top of the housing, I also own an MX6 which recently has been smelling of anti freeze when hot, these have the same ast so I thought Iwould take the one from the MX6 and fit it on the FD only to find a crack in exactly the same place.
Reparing the cracks with J-b weld has cured the problem on both cars.
might be worth checking yours.

[Stu.Wilson]

Thats good to know so how do I know of I have this problem, is there a quick way to check to see if I have waterseal failure would a pressure test on the cooland system tell me this?

When i suspected water seal failure again last year, i removed the bottom 2 spark plugs and the EGI fuse (i think it was this one from memory, the one that stops fuel coming to the engine on the fuse unit on the battery) and then got my mate to crank it over while i check for any signs of water coming out. This might be worth a try.

Hopefully it is just a coolant system leak, but these can be a huge pain to locate. It was last Aug my car started losing coolant and i only have just located the main leak, did find several though.

It turned out to be the metal coolant rail for the turbo pack, it had a hair line crack in it. Which would only leak when hot and not when cold. But when it leaked when hot, the water would evaporate straight away due to the location of the leak (right next to the first tub, so lots of heat). So try this area.

Also have a look for a small coolant pipe under the throttle body (leads to just above the upper rear spark plug), it\'s only about 3" long but i also had small leak from their.

And

The long coolant pipe that runs from the throttle body down by the bulk head, i had small leak on that too.

But don\'t forget to check that the AST tank and cap are in good condition, make sure the cap has no scum/scale built up around the metal ring in the middle. This needs to sit flush in the AST tank to create a seal, also make sure the AST tank is scum/scale free where the AST cap sits. If it\'s not scrap off any build up.

If you replace any pipe\'s use Mazda genuine parts, they are much easier to fit on! and quit cheap too.

Best of luck with this mate, hope this sort off helps. Feel free to Email or PM me.

Stu
\'stuart_wilson1@yahoo.co.uk\'