Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: leon on September 24, 2008, 10:04:58 PM

Title: Coolant leak - may be dead engine \\o/
Post by: leon on September 24, 2008, 10:04:58 PM
Well i\'m looking at the possibility that i\'ve finally been bitten by a milestone of owning a rotary car: The engine going pop.
[STORY]
Yesterday i was doodling along on the m621/62 When suddenly the add coolant buzzer came on and the heat started to rise! I cut the engine then pulled over onto the hard shoulder :p I had to let her cool and my old man came along an hour and a half later we put about a tea cup full of water into the car!? At the time I was surprised at just how little was lost and that I could not find a leak for the life in me while at the side of the road.

Anyway today the car turned over first time and started up and I shouted to the gods in praise as not a single puff of white smoke came out of her ass! drove to work without a worry or a bleep. came out of work and agian filled up a cup full of fluid and drove home, i had a few beeps come on at random times while stopped saying "add coolant" i ignored them knowing that there was still coolant int he engine and the temperature was stable.

Got the car home and let her cool down, again i topped the engine up with a cup full of fluid and started her up first time (no smoke) I then noticed she ****ed all over the floor when the radiator fans came on the leak seemed to come from the expansion tank.
[/STORY]
As i write this i seem to be talking myself out of a water journal failure o.o
 
How hard is it to get to the overflow tank to find out where exactly the leak is if any? and does this sound symptomatic of a coolant seal failure?

Cheers
Guys an gals.

Now more Guinness :guinness
Title: Coolant leak - may be dead engine \\o/
Post by: Carl on September 24, 2008, 10:34:11 PM
It might be your pressure cap getting a bit weak.
It is very important to make sure that you have no air in the system when you refill it.
Regards
Carl
Title: Coolant leak - may be dead engine \\o/
Post by: m1tch on September 24, 2008, 11:02:05 PM
Also, did the engine temp read above \'H\' on the temp guage?
Title: Coolant leak - may be dead engine \\o/
Post by: leon on September 24, 2008, 11:26:44 PM
Thank you for the reply Carl :) Is there anyway to test or is it best just to replace? The engine was shut of the moment the gauge started to move :)
Title: Coolant leak - may be dead engine \\o/
Post by: TTMan on September 25, 2008, 12:38:41 PM
this happened to my car exactly the same, coolant buzzer coming on and losing water from the overflow and it was wrong pressue coolant cap hopefully a new one will solve your problem, lot less expensive than a rebuild! probably worth flushing your system just to be safe
Title: Coolant leak - may be dead engine \\o/
Post by: leon on September 25, 2008, 02:56:28 PM
Im amazed at just how annoying it is finding another 0.9 bar cap or maybe im just missing a trick. :Thumbsup!
Title: Coolant leak - may be dead engine \\o/
Post by: fil_auto on September 25, 2008, 03:05:20 PM
try jimmys bud or one of the other vendors / specialists - give them a quick mail or buzz and I\'m sure one them will be able to sort you out....
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 09, 2008, 10:23:14 AM
Holy post revival batman!

This problem is driving me nuts :driving I\'ve changed the pressure cap now for a new 0.9 bar cap after trying one from an MX5. The problem does seems to be considerably less prevelent now but last night I did lose coolant and start to get hot again. The engine got killed before the gauge had moved more than a few mm.

What is annoying me about this problem is that its not consistant, I can go for a number of days without the coolant buzzer then when I get stuck in trafic it becomes more of an issue. No problems with startup (no firing on a single rotor) no plooms of white smoke nothing :3Confused yet the water is being pushed out of the expansion tank at a trickles pace again not constantly. Slap me if my logic is wrong here, but if it was a leak into the rotor housing wouldnt the pressurised system flood the chamber the moment you kill the engine thus making a restart hard? :spank

The only realisation that hits me now is that the cap on the filler neck is still the old one, clutching at staws here but is it possible if thats leaking its causing the system not to pressurise properly and thus overheat?

Cheers Guy an Gals.
Title: Coolant leak - may be dead engine \\o/
Post by: RemarkLima on October 09, 2008, 12:01:34 PM
Sorry if I\'ve missed this in the tread, but you\'re sure the fans are working? And switching on at the right time etc?
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 09, 2008, 12:25:36 PM
Good point, but my fans are working :) I used them to accelerate the cooldown of my engine while on the hardshoulder. I\'ve also seen them come one while iding the car and working under the bonnet :)
Title: Coolant leak - may be dead engine \\o/
Post by: Hayward North on October 09, 2008, 12:37:37 PM
Your problem could be a sticking thermostat, it may be working most of the time but the odd occasion where its sticking it could be blocking the passage way to the radiator thus making the water in the block boil.
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 09, 2008, 01:03:58 PM
Would this also give reason as to why it forces fluid out of the expansion tank? :wave
Title: Coolant leak - may be dead engine \\o/
Post by: Hayward North on October 09, 2008, 01:18:03 PM
Yes as when it unsticks its expanding back into the radiator side and making it boil over into expansion tank, i have seen it countless times on mazdas.
Im not saying this is what it is, but i think your next move is changing the thermostat and seeing how you go from there.
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 09, 2008, 05:07:06 PM
Cheers steve it does mate sense :wave
Title: Coolant leak - may be dead engine \\o/
Post by: 907 on October 09, 2008, 09:01:21 PM
could be many things TBH, I have had this same problem a couple of times and on both ocasions it has turned out to be leaking pipes that go under the plenum.  The easiest way to check is to bypass the AST tank and pressurise the water system and see if it holds pressure. Chances are it wont.  I modifed a ford probe pressure cap to take a hose that goes to a pressure guague and via a valve to a foot pump to do the test.  The first time I had this problem it turned out I had four seperate small leaks.
If its the pressure cap leaking chances are you will get water leaking out dripping off the R.H. brake duct.
Neil
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 10, 2008, 09:34:24 AM
Yeah its coming out over the brake duct but thats from the expansion tank (you had the same problem from a leaky hose?) I did the champers test and get foam rather than a bubbles (Then again the chamers test is un reliablei read) I think im going to have to replace the thermostat and all the coolant hoses to get to the bottom of this :rolleyes:
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 10, 2008, 07:29:14 PM
Okay something has defo gone bang in the coolant system, found myself a peice of rubber today! Whats the best way of finding out if the seal has gone and its not one from say the turbo or part of the thermostat?

Reason i say turbo system is that i got a nice ploom of white smoke today out the back while running down from 8k  and the champers test just gives me fizz rather than definitaive bubbles.. however the coolant does froth up once it leaves the filler neck o.O

Would popping the lower spark plug and turning the rotors give me a definitive answer to if the seals on the engine are gone?
Title: Coolant leak - may be dead engine \\o/
Post by: Hayward North on October 10, 2008, 07:44:50 PM
Rubber in the coolent ? if so then what colour is the rubber ?
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 10, 2008, 08:06:08 PM
it was a black thin piece, rather indescript i know, light was fading and being a cluts i dropped it back into the neck :( twas about an inch and bit long though so not a small thing.
Title: Coolant leak - may be dead engine \\o/
Post by: BenLewisMav on October 10, 2008, 11:47:18 PM
Did it look a bit like an elastic band? If so it sounds a bit like a water seal...
But dont just jump to conclusions, pressure test it! If that doesn\'t give you a definately answer, there\'s a product you can use to test whether hydrocarbons (produced during combustion) are present in the coolant.. Do both of these and you should know the answer!
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 11, 2008, 12:11:56 PM
Cheers for the help guys its really appreciated :)  I know I may sound like I dither on a bit but I prefer to be methodical. I\'m going to pull the plugs today and hand crank the engine to see if i get wet. other than that try and find somebody local who has a pressure tester or DIY make one?
Title: Coolant leak - may be dead engine \\o/
Post by: BenLewisMav on October 11, 2008, 01:08:09 PM
Not sure if you\'d be able to pressurise the cooling system enough just from cranking to cause it to leak into the chamber enough for you to notice? Definately worth investing time/money into buying or making a pressure tester
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 11, 2008, 02:13:10 PM
Yeah that\'s the job now (First version was a failure now for version 2!), I did the ol test of taking the bottom spark plugs out and rotating the engine, did not get a single drop of water out of the holes :(  least that tells me i don\'t get water sitting in the rotor housings! but its still not 100% definite.
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 11, 2008, 05:25:09 PM
Oh hell now im confused dot com! I made a pressure tester and put it on pressurized the system near to 20 psi (factory manual test) and the coolant is audibly heard pushing into the expansion tank! as well as accompanying wet foot.. :2eek Thats not right is it?
Title: Coolant leak - may be dead engine \\o/
Post by: leon on October 11, 2008, 06:00:39 PM
Im being blond.. ofcourse 20psi will empty the car the ast only has an 13psi cap.... anway the coolant system seems happy to sit at 13psi and holds :3Confused