Common Points of Engine Failure

tweiss3 · 02-25-2011, 09:59 AM

I've been reading (in my never ending strive to accumulate information) of a few engine failures, and I thought (i searched) that it would be nice to have a single thread about the different types of engine failures. So far the few I have had are as follows.

1)Bearing failure for the e-shaft
- usually oil related, sometimes overheating and over reving
2)Apex seal failure, chipping, scoring
- detonation the cause?
3)Carbon build up causing the rotors to become un-ballanced
-it happens, but can be prevented mostly, also the water cleaning can fix carbon already built up
4)Seal/compression can be lost
-side seals, seal springs loose springyness, improper clearances, wear on the housings, apex seals, cold ass weather doesn't ever help, oil starvation (OMP failure or lack of proper ratio of premix)

Are there any others? Anyone care to go further into what causes these failures, and what can be done to prevent these? I'm just wondering, and of course, knowing failure points helps your maitnence, and your tuning/building knowledge.

88turboii · 02-25-2011, 10:25 AM

another problem i see a lot is coolant seal failure, but after tearing down the engine, there is nothing obviously wrong with the coolant seals. Its like they flatten out after a while or something. ive torn down about 4 engines, and have seen this on two of them. symptoms were overflowing coolant overfill and white smoke/running one rotor on startup

tweiss3 · 02-25-2011, 10:35 AM

what would cause that, the extreme heat and torsion of the motor? Other than just age?

***TitaniumTT*** · 02-25-2011, 10:46 AM

Quote:

Originally Posted by tweiss3

what would cause that, the extreme heat and torsion of the motor? Other than just age?

Overheating maybe, generally what happens with the S4/5 engines is the coolant seal support on the iron in the lower corners gets eaten away by corrosion. The steel piece actually falls away and the coolant/fire seal moves and looses contact. It lets exhaust gases into the coolant system when the engines running, then when you shut it down, the pressure of the coolant system pushes the coolant into the combustion chamber. Double whammy.

I tore an engine down about a month ago.... this was the CLEANEST engine that I have ever pulled apart that wasn't mine. This thing was mint.... coolant seal let loose as described above. It's cool though, bought the 'vert for dirt cheap becuase of that coolant seal.

PercentSevenC · 02-25-2011, 10:37 AM

http://rotarycarclub.com/rotary_foru...ead.php?t=9117

tweiss3 · 02-25-2011, 10:46 AM

dammit, i must not have gone back far enought, thanks

chibikougan · 02-25-2011, 02:45 PM

How about exhaust sleeve failure.

I know Brian had this happen I don't think his engine failed due to it. It was the opposite rotor also I think.

chibikougan · 02-25-2011, 02:48 PM

Whoa! Muscle Spasm

***TitaniumTT*** · 02-25-2011, 03:04 PM

Yup, been there, been fucked by that. Rear rotor, sleeve failed, engine perfectly healthy... the three turbo's that the chunks went through...... not so much

tweiss3 · 02-25-2011, 03:08 PM

How does that happen? Any way to prevent it?

***TitaniumTT*** · 02-25-2011, 03:26 PM

I'm gonna go with high EGT's over a sustained period of 4k rpm cruising for 20+ hrs strait on puked turbo's thus the EMAP's where very high.

And I'll save Peter the trouble

Quote:

Originally Posted by Rice Racing

Common points of engine failure = bdc/hc

tweiss3 · 02-25-2011, 04:03 PM

so NA this shouldn't be an issue at all?

02-25-2011, 09:59 AM	#1
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio iTrader: (0) Posts: 319 Rep Power: 15	Common Points of Engine Failure I've been reading (in my never ending strive to accumulate information) of a few engine failures, and I thought (i searched) that it would be nice to have a single thread about the different types of engine failures. So far the few I have had are as follows. 1)Bearing failure for the e-shaft - usually oil related, sometimes overheating and over reving 2)Apex seal failure, chipping, scoring - detonation the cause? 3)Carbon build up causing the rotors to become un-ballanced -it happens, but can be prevented mostly, also the water cleaning can fix carbon already built up 4)Seal/compression can be lost -side seals, seal springs loose springyness, improper clearances, wear on the housings, apex seals, cold ass weather doesn't ever help, oil starvation (OMP failure or lack of proper ratio of premix) Are there any others? Anyone care to go further into what causes these failures, and what can be done to prevent these? I'm just wondering, and of course, knowing failure points helps your maitnence, and your tuning/building knowledge. __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

02-25-2011, 10:25 AM	#2
88turboii destroy, rebuild, repeat Join Date: Feb 2008 Location: Charleston, SC iTrader: (0) Posts: 395 Rep Power: 17	another problem i see a lot is coolant seal failure, but after tearing down the engine, there is nothing obviously wrong with the coolant seals. Its like they flatten out after a while or something. ive torn down about 4 engines, and have seen this on two of them. symptoms were overflowing coolant overfill and white smoke/running one rotor on startup __________________ 1993 RX-7 Touring MB, stockport 13B-REW, 9.4CR rotors, T04S 60-1/p-trim single turbo 1986 RX-7 Base project track beast

02-25-2011, 10:35 AM	#3
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio iTrader: (0) Posts: 319 Rep Power: 15	what would cause that, the extreme heat and torsion of the motor? Other than just age? __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

02-25-2011, 10:46 AM	#6
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio iTrader: (0) Posts: 319 Rep Power: 15	dammit, i must not have gone back far enought, thanks __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

02-25-2011, 03:04 PM	#9
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	Yup, been there, been fucked by that. Rear rotor, sleeve failed, engine perfectly healthy... the three turbo's that the chunks went through...... not so much __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

02-25-2011, 03:08 PM	#10
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio iTrader: (0) Posts: 319 Rep Power: 15	How does that happen? Any way to prevent it? __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

02-25-2011, 04:03 PM	#12
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio iTrader: (0) Posts: 319 Rep Power: 15	so NA this shouldn't be an issue at all? __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles