seal damage
12-31-10, 02:06 PM
#1
seal damage
I am picking up a s5 n/a in a month or so with a blown rear rotor and only 79,000 km. I have seen the damage my engines suffered when a 2 piece seal blows, however I am wondering if the rotor and housing "may" have survived the stock 3 piece seal failure?
12-31-10, 02:11 PM
#2
Engine, Not Motor
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Maybe, maybe not. 
It's sort of a crapshoot either way. But generally, any stock apex seal failure means damage to at least the rotor housing unless you are incredibly lucky and it was immediately swept out of the exhaust port. Unfortunately, the stock 3 pieces seals tend to "roll" out of the slot when they go, causing big damage to the housing and the rotor.
It's sort of a crapshoot either way. But generally, any stock apex seal failure means damage to at least the rotor housing unless you are incredibly lucky and it was immediately swept out of the exhaust port. Unfortunately, the stock 3 pieces seals tend to "roll" out of the slot when they go, causing big damage to the housing and the rotor.
12-31-10, 02:49 PM
#5
on a side note, the non turbo cars have little room for the debris to get spit out of the exhaust which is why i said what i said. although it is rather uncommon for non turbo engines to spit a seal, it could just be carbon locked and jammed up the rotors, in which case you may be able to revive the engine with some MMO/ATF and a water treatment.
only way to tell if it did spit a seal is to inspect the seals through the exhaust ports or spark plug holes. it's usually pretty apparent that the motor half is trashed without tearing the engine apart.
only way to tell if it did spit a seal is to inspect the seals through the exhaust ports or spark plug holes. it's usually pretty apparent that the motor half is trashed without tearing the engine apart.
12-31-10, 06:43 PM
#6
The current owner had a dealer diagnose it 12 years ago and it lost compression on the back rotor. She still drove it about 40 miles in that state before having it towed to the dealer. She bought the n/a base model new in 1989 and chose it over the TII because the power of the TII seemed like too much for her. I am hoping to get lucky and do a MMO revival and discover a stuck seal getting free do to a driving miss daisy easy driver carboning things up...the car is in amazing condition!!
None the less, I have a spare S5 with good compression in my garage.
None the less, I have a spare S5 with good compression in my garage.
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01-02-11, 01:27 PM
#10
i use MMO all the time on engines that are siezed or have 0 compression due to stuck seals. once running though i use carb cleaner to decarbonize severely carboned up engines as water usually is for light stuff. carb cleaner along with the MMO helps break up carbon in the siezed motor cases.
MMO is a lightweight detergent based lubricant, very similar to hydraulic fluid and transmission fluid which is why i don't suggest using it as a premix. it is a good for decarbonizing parts, which is why so many old school mechanics use ATF to flush piston engine crankcases.
MMO is a lightweight detergent based lubricant, very similar to hydraulic fluid and transmission fluid which is why i don't suggest using it as a premix. it is a good for decarbonizing parts, which is why so many old school mechanics use ATF to flush piston engine crankcases.
Last edited by RotaryEvolution; 01-02-11 at 01:32 PM.
01-03-11, 10:28 AM
#11
Engine, Not Motor
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It's funny though, how ineffective ATF actually is on carbon. Years ago I tested a bunch of these products on carbon'ed up rotors and ATF was about the worst. WD-40 worked better, as did PB Blaster. The best was carb cleaner and diesel fuel. I didn't test MMO though. It is a bit harder to find in Canada.
Guess I should dig up the pictures and post the comparison to my website.
Guess I should dig up the pictures and post the comparison to my website.
01-04-11, 03:31 PM
#13
01-04-11, 04:10 PM
#16
Just broke down 3 engines yesterday: 1S5 and 2S4's.
The best/worst was an S4 Mazda reman where then in the aux acuator sleeve rattled loose and got sucked through the motor. It bent up the intake port as it came through and grinded against the rotor. It might have actually broken in half as the rotor looked like it had been shot multiple times w/ a .22. Sucks cuz it also ruined a sub 20k housing....
The best/worst was an S4 Mazda reman where then in the aux acuator sleeve rattled loose and got sucked through the motor. It bent up the intake port as it came through and grinded against the rotor. It might have actually broken in half as the rotor looked like it had been shot multiple times w/ a .22. Sucks cuz it also ruined a sub 20k housing....
01-04-11, 11:44 PM
#18
my REPU sat for almost 25 years, was carbon locked and MMO worked it loose like a charm, had multiple cars given to me also that MMO loosened the stuck seals on. i don't swear by MMO by any means but i have never seen it harm any motors while bringing them back to life when most people would have written them off. carb cleaner and 2 stroke oil would probably work equally as well but i prefer the thinner MMO since it can work into recesses better than 2 stroke oil and lubricate better than carb cleaner can.
Last edited by RotaryEvolution; 01-04-11 at 11:49 PM.
01-20-11, 08:16 PM
#20
Well, I bought the Amsoil Powerfoam. The car arrives this Saturday so we'll give the Amsoil a test.
Step 1: I am going to spray both rotors down through the spark plug holes and just turn it over by hand.
Step 2: Turn the engine by hand both directions daily over 3-4 days
Step 3: Compression test
Step 4: Assuming lost compression in one of the rotors still
, fire the bitch up and warm it up real well.
Step 5: repeat steps 1,2
Step 6: cross fingers, say a prayer, apologize for all my discretions (this could take a while
), and do another compression test
Step 7: compression or no compression, fire the bitch up, warm it real well, maybe drive it and see if I get lucky
loosening up any seal restricting carbon.
Step 8: If all fails, pull the engine and install my spare.
Step 1: I am going to spray both rotors down through the spark plug holes and just turn it over by hand.
Step 2: Turn the engine by hand both directions daily over 3-4 days
Step 3: Compression test
Step 4: Assuming lost compression in one of the rotors still
, fire the bitch up and warm it up real well.Step 5: repeat steps 1,2
Step 6: cross fingers, say a prayer, apologize for all my discretions (this could take a while
), and do another compression testStep 7: compression or no compression, fire the bitch up, warm it real well, maybe drive it and see if I get lucky
loosening up any seal restricting carbon.Step 8: If all fails, pull the engine and install my spare.
