Series II Compression Test Results & Discussion - RX8Club.com

Notices
Series II Technical and Trouble shooting Discuss technical details for the Series II RX-8 and any issues or problems you are facing

Series II Compression Test Results & Discussion

Old 04-05-2015, 02:59 AM
  #1  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
Series II Compression Test Results & Discussion

Hi all. I thought I'd start this thread to compile compression test data on Series II RX-8s and also to get your advice on my situation. Just had a compression test done today.

Basic info:
2009 R3
97,000 miles

Compression test results:

Rotor 1 - Test 1
RPM: 332
740 kPa (107 psi)
760 kPa (110 psi)
760 kPa (110 psi)

Rotor 1 - Test 2
RPM: 332
740 kPa (107 psi)
770 kPa (112 psi)
750 kPa (109 psi)

Rotor 2 - Test 1
RPM: 330
830 kPa (120 psi)
820 kPa (119 psi)
830 kPa (120 psi)

Rotor 2 - Test 2
RPM: 330
830 kPa (120 psi)
830 kPa (120 psi)
820 kPa (119 psi)

History:
Owned since new (DEC 2009) Average oil changes every 4.5k. Up to 75k miles use was 60% highway, thereafter I would say 90% highway. Cat replaced @ 6k miles, most likely plugged up while car had been sitting on dealer lot. Spark plugs replaced @ 36k, 66k, and recently just now at 97k (more on that later). Coils replaced at 77k. While many of you will criticize me for going that long (and in hindsight I'll probably agree), this is consistent with the schedule recommended in the owner's manual. I take it to 7500+ rpm on a near daily basis, on an empty stretch of road on my way to work (2nd, 3rd and 4th gear). Only started premixing recently (3 tanks so far). So my car can be a data point on what you might expect to happen to an SII if you keep to Mazda's maintenance schedule.

Potentially related symptoms:
Occasionally will take an extra second or so of cranking to fire up (usually fires up in < 2s) when warm. Only happens after a little bit of cooling time (7k redline on startup). This has been going on for some time.

The last few months there has been an occasional stumble at idle when the engine is warm. Could be due to crudded up spark plugs. Recently, there seems to be a slight loss of top-end power. I noticed this because on an uphill stretch of road where I can go WOT, the car tops out at a lower speed than before.

Potentially related problem:
Asked dealer to swap in new plugs while they were doing the compression test. Tech reported that Rotor 1 leading spark plug had been loose. On closer examination I see that the crush washer was not at all compressed, so it was never torqued down properly, and there is carbon crud at base of spark plug threads. Plugs were last changed by this same dealership, so it was like this for 30k miles Could this have caused carbon buildup & lower compression on Rotor 1?

Now I would be OK with those compression #s if they were at 250 rpm, but they are at 330. (At least my starter is doing really well ). Service advisor insisted that the compression #s were passing even though I asked about normalizing the values to 250 psi. He suggested a de-carb w/ seafoam. When I got home, I checked the Series II workshop manual, and I see that the minimum is about 760 kPa even at 300 rpm, so 740 kPa @ 330 rpm would seem like it's clearly failing.

This has been a frustrating day, because it seems like Rotor 1 is on it's way out, but being propped up by Rotor 2, so no major driveability issues yet. Apparently there is enough ambiguity in the test results for the dealer to claim the compression is still good? I welcome your suggestions for best course of action. I hope other people post their SII compression results and outcomes as well.

Thanks!
Jastreb is offline  
Old 04-05-2015, 03:03 AM
  #2  
Registered
iTrader: (46)
 
9krpmrx8's Avatar
 
Join Date: Jan 2007
Location: San Antonio, Texas
Posts: 33,738
Thanked 328 Times in 267 Posts
Rotor 1 is definitely below spec, they need to replace the engine. Sucks about the loose plug. And yeah the 09-11 starter is powerful, I have one in my 04'.


9krpmrx8 is offline  
Old 04-05-2015, 08:24 AM
  #3  
weeeeeeeeee
iTrader: (11)
 
ShellDude's Avatar
 
Join Date: Jun 2008
Location: Outside Philadelphia
Posts: 4,136
Thanked 8 Times in 7 Posts
Zoom zoom power clean it. If pressed that's what the dealer would do and your numbers would likely be above the line afterwards.
ShellDude is online now  
Old 04-05-2015, 11:19 AM
  #4  
Water Foul
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 2,202
Thanked 145 Times in 117 Posts
If you are still under warranty, I would press hard on the dealer for an engine replacement. 97K miles is cutting it close. If your dealer won't work with you, find one that will.
Steve Dallas is offline  
Old 04-05-2015, 12:01 PM
  #5  
Koi no Ousama
iTrader: (25)
 
TeamRX8's Avatar
 
Join Date: Apr 2005
Posts: 20,551
Thanks: 0
Thanked 278 Times in 229 Posts
Even if it was 99,999 miles it should still be covered. 100,001 and they wouldn,t think twice to deny, so stick to your guns. Sounds like you've been a loyal customer getting your service work done there. Get your paperwork together, get a meeting with the service manager, use your prior service history noting the sparkplug issue, and be firm but professional/calm/polite about making it clear you know that R1 is out of spec ...
TeamRX8 is offline  
Old 04-05-2015, 09:46 PM
  #6  
Registered
iTrader: (46)
 
9krpmrx8's Avatar
 
Join Date: Jan 2007
Location: San Antonio, Texas
Posts: 33,738
Thanked 328 Times in 267 Posts
^ yep. I got a reman installed under warranty at 96,000 miles.
9krpmrx8 is offline  
Old 04-08-2015, 02:12 PM
  #7  
Registered
 
Join Date: Oct 2013
Location: GA
Posts: 24
Thanks: 0
Thanked 0 Times in 0 Posts
If you don't mind me asking... If I was to be completing all of these services myself and have receipts of every time I purchased the maintenance items, documented mileage at time of service, would Mazda have an issue with replacing the engine IF it where needed. I'm still under the 8yr/100k core warranty on my 09 R3 w/ 47k mi. If that paper trail isn't good enough, then am i screwed for the day I need an engine? If it still falls in the warranty window @ the time that is.
parnellj48 is offline  
Old 04-08-2015, 02:35 PM
  #8  
Verbose SuperMod
iTrader: (2)
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,683
Thanks: 0
Thanked 137 Times in 76 Posts
You just have to show maintenance records. I put all mine in MazdaUSA owners section (I did all the maintenance on from ~20k to 113k), and it was good enough for my replacement at 96,990 miles. Didn't even question it.
RIWWP is offline  
Old 04-08-2015, 02:39 PM
  #9  
Registered
 
Join Date: Oct 2013
Location: GA
Posts: 24
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by RIWWP View Post
You just have to show maintenance records. I put all mine in MazdaUSA owners section (I did all the maintenance on from ~20k to 113k), and it was good enough for my replacement at 96,990 miles. Didn't even question it.
Cool. Thank you.
parnellj48 is offline  
Old 04-08-2015, 04:00 PM
  #10  
Registered
 
Nadrealista's Avatar
 
Join Date: Feb 2011
Location: Here
Posts: 476
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by TeamRX8 View Post
Even if it was 99,999 miles it should still be covered. 100,001 and they wouldn,t think twice to deny, so stick to your guns. Sounds like you've been a loyal customer getting your service work done there. Get your paperwork together, get a meeting with the service manager, use your prior service history noting the sparkplug issue, and be firm but professional/calm/polite about making it clear you know that R1 is out of spec ...
what he said, they owe you a new/reman engine replacement!

btw where are you originally from?
Nadrealista is offline  
Old 04-08-2015, 07:45 PM
  #11  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
Is it reasonable for the dealer to want to do a de-carb first? From what I've read here it can help the seals seat better, or it can do absolutely nothing... Can this be counter-productive?

Nadrealista, originally I'm from Russia.
Jastreb is offline  
Old 04-08-2015, 07:51 PM
  #12  
Verbose SuperMod
iTrader: (2)
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,683
Thanks: 0
Thanked 137 Times in 76 Posts
A proper decarb can indeed improve compression.

However, there are a lot of "IFs" around that. It has to be done right, AND carbon buildup can be the only reason for compression loss. If you have had a lot of carbon buildup that unseated the seats and they wore badly, decarbing could hurt compression. It's a big unknown to do so really.
RIWWP is offline  
Old 04-08-2015, 08:34 PM
  #13  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
I feel like this is going to be a long process...
Dealer rep claimed that their computer didn't show my vehicle being under any kind of warranty. Called MNAO to confirm warranty coverage (of course I'm still covered), and told dealer rep to call MNAO to verify on his end.

Step 0/10
Jastreb is offline  
Old 04-08-2015, 08:36 PM
  #14  
Verbose SuperMod
iTrader: (2)
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,683
Thanks: 0
Thanked 137 Times in 76 Posts
There was a dealer in RI that got an 8 in for "trouble starting", they did a compression test and found the engine to be badly failing. The handed the owner a repair estimate. $10,000 for the engine, $6,000 for the labor to install it.

If that wasn't bad enough, only when he pitched a fit over it did they "remember" that his car was under the 5yr 60k powertrain warranty still and replaced it free of charge.




Dealers can be such ********.
RIWWP is offline  
Old 04-09-2015, 08:34 AM
  #15  
Water Foul
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 2,202
Thanked 145 Times in 117 Posts
Originally Posted by RIWWP View Post
You just have to show maintenance records. I put all mine in MazdaUSA owners section (I did all the maintenance on from ~20k to 113k), and it was good enough for my replacement at 96,990 miles. Didn't even question it.

Hmmm... Did not know this even existed. I learn something from you every day. Now perhaps I can just buy OEM filters online and stop paying the dealer for nothing. :D
Steve Dallas is offline  
Old 04-12-2015, 12:04 AM
  #16  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
Good news everyone!
Dealer rep was able to verify warranty coverage, and I should be getting a new motor! I think the problem was that so few SII's have needed it, that they were not familiar with the particular engine core warranty for the SII. It does not come up when they look up the VIN #.
Jastreb is offline  
Old 04-14-2015, 02:01 AM
  #17  
Registered
 
Join Date: Mar 2015
Location: West Michigan
Posts: 24
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by RIWWP View Post
You just have to show maintenance records. I put all mine in MazdaUSA owners section (I did all the maintenance on from ~20k to 113k), and it was good enough for my replacement at 96,990 miles. Didn't even question it.
I just signed up to the MazdaUSA MyMazda owners section. I am curious as to what you put down as your service facility? I plan on doing some work myself on my car (oil changes, brakes; ignition coils, wires, and plugs etc.) I currently have 3 years and 60,000ish miles left on my engine warranty (2010 GT w/40,000+ miles) and would like to keep myself covered if something were to happen to it.
zerogunner is offline  
Old 04-23-2015, 07:49 PM
  #18  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
Car is currently at the dealer, should be getting a reman next week. Keeping my fingers crossed that everything goes well...
Jastreb is offline  
Old 04-25-2015, 07:53 PM
  #19  
Registered
 
Join Date: Oct 2013
Location: GA
Posts: 24
Thanks: 0
Thanked 0 Times in 0 Posts
I'll repost my results after doing proper homework. Sry for my stupidity.

Last edited by parnellj48; 04-25-2015 at 09:49 PM.
parnellj48 is offline  
Old 04-25-2015, 09:27 PM
  #20  
40th anniversary Edition
 
gwilliams6's Avatar
 
Join Date: May 2008
Location: Grapevine, Texas
Posts: 2,757
Thanked 60 Times in 53 Posts
RIWWP can you direct Jastreb to your warnings about too much sealant used in remans and what to watch for and change with his cooling system once he has his reman in. Your warnings were very important, so he doesn't have a reman premature failure due to a clogged cooling system.
gwilliams6 is offline  
Old 04-25-2015, 10:23 PM
  #21  
Verbose SuperMod
iTrader: (2)
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,683
Thanks: 0
Thanked 137 Times in 76 Posts
Mobile only till monday. Unsure how many times you make a request to me without letting me know.

New owner's thread i think, if not my site rx8help.com, if not, just search reman excessive sealant, you will find info
RIWWP is offline  
Old 04-27-2015, 05:37 PM
  #22  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
Mystery compression improvement

Dealer just called me and informed me that they did 2 more compression tests on the original engine.

The results from the last test:
Rotor 1
RPM: 310
850 kPa (123 psi)
830 kPa (120 psi)
850 kPa (123 psi)

Rotor 2
RPM: 314 psi
920 kPa (133 psi)
940 kPa (136 psi)
930 kPa (135 psi)

Service rep says this is the strongest Renny they've seen in a very long time and there's absolutely nothing wrong with it. Since the previous (see original post) compression test, I had driven it for a week and a half. The only things that I had been doing differently was pre-mixing with Royal Purple TCW-III and new spark plugs. And somehow I magically gained 10+ psi of compression across the board ?

Also was told misfire count for last drive cycle was 13, which doesn't actually mean too much without knowing what that drive cycle was.

I asked specifically about testing at proper engine temps, and was assured the correct procedure was followed. Picking the car up tomorrow after having wasted a week and $100 on a rental car . I may go get another test done at another dealership just to be sure...
Jastreb is offline  
Old 04-28-2015, 09:01 AM
  #23  
Registered
 
Nadrealista's Avatar
 
Join Date: Feb 2011
Location: Here
Posts: 476
Thanks: 0
Thanked 0 Times in 0 Posts
The only way I would believe that magically improved compression numbers is if I was standing right next to the tech during the compression test, so I strongly recommend you do just that. And don't premix before the compression test!
Nadrealista is offline  
Old 04-28-2015, 12:14 PM
  #24  
Registered
Thread Starter
iTrader: (1)
 
Join Date: Apr 2010
Location: SoCal/LA Metro
Posts: 244
Thanked 12 Times in 11 Posts
Originally Posted by Nadrealista View Post
The only way I would believe that magically improved compression numbers is if I was standing right next to the tech during the compression test, so I strongly recommend you do just that. And don't premix before the compression test!
The last tank of gas that I put in the car didn't have premix. I'm taking it somewhere else, I'm done with these people - they wasted my time for an entire week.

To make things worse, on my way back from work last night I hit a random-*** box in the middle of the freeway which f*cked up the bumper on the rental car. I guess the silver lining is that had been in the 8, it would have probably taken out the oil cooler also.
Jastreb is offline  
Old 05-17-2015, 02:24 PM
  #25  
Registered
iTrader: (2)
 
Shumster's Avatar
 
Join Date: Jun 2012
Location: Calgary, AB
Posts: 293
Thanks: 0
Thanked 0 Times in 0 Posts
What ever happened to this?
Shumster is offline  

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Series II Compression Test Results & Discussion


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.