Having a hard time starting when warm, compression isn't low!?
04-09-2013, 10:29 AM
#1
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
Having a hard time starting when warm, compression isn't low!?
Title sums it all up. My car starts okay enough when it's cold, but after it's been nice and warmed up, I have to spend 10-20 seconds cranking waiting for it to turnover. I just replaced the Spark plugs/wires/coils, then went and had the compression tested, and while I'm not at minimums, I'm not at maximum levels either. What else has the potential to cause this? What else can I check?
04-09-2013, 10:32 AM
#2
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes
on
110 Posts
Hmm, it's almost always compression.
The other two possibilities are a fuel pump failure (Although this typically means that it shut off when driving, and will refuse to start until it cools down later on), or the starter itself is failing and maybe the heat from the engine/transmission is weakening it just that bit further.
What was the compression test results? Scores + RPM
The other two possibilities are a fuel pump failure (Although this typically means that it shut off when driving, and will refuse to start until it cools down later on), or the starter itself is failing and maybe the heat from the engine/transmission is weakening it just that bit further.
What was the compression test results? Scores + RPM
04-09-2013, 11:24 AM
#5
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes
on
110 Posts
NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
^ the only entry in the diagnostics factory manual that I am seeing. It does have a huge list, but not many things are engine temp related.
^ the only entry in the diagnostics factory manual that I am seeing. It does have a huge list, but not many things are engine temp related.
Vacuum leakage
Air leakage from intake-air system
Air suction at intake-air system (between MAF sensor and intake ports)
Air cleaner restriction
Improper operation of drive-by-wire control system
Drive-by-wire control system operates in fail-safe mode
Throttle body malfunction (stuck open)
SSV stuck open
SSV solenoid valve malfunction (stuck open)
APV stuck open*
APV motor malfunction*
APV position sensor malfunction*
Poor fuel quality
Jet air mixing system malfunction (restriction or leakage in air passage)
Inadequate fuel pressure
Pressure regulator malfunction (integrated in fuel pump)
Fuel injector (FP1) (RP1) is clogged.
Open or short in fuel injector (FP1) (RP1) control signal circuit
Restriction in exhaust system
Purge solenoid valve malfunction (stuck open)
Improper air/fuel ratio control (abnormal ECT signal to PCM)
Erratic signal form eccentric shaft position sensor
MAF sensor contamination (abnormal signal to PCM)
MAF sensor improper installation
Low engine compression
Engine internal malfunction
Abnormal engine oil condition (viscosity, deterioration)
Low oil pressure
Excessive fuel pressure
Air mixed in oil line
Metering oil pump malfunction
Leakage or clogging in oil pipe
Leakage or clogging in oil nozzle
Starting system malfunction
Spark leakage from high-tension leads
Spark plug malfunction
Air leakage from intake-air system
Air suction at intake-air system (between MAF sensor and intake ports)
Air cleaner restriction
Improper operation of drive-by-wire control system
Drive-by-wire control system operates in fail-safe mode
Throttle body malfunction (stuck open)
SSV stuck open
SSV solenoid valve malfunction (stuck open)
APV stuck open*
APV motor malfunction*
APV position sensor malfunction*
Poor fuel quality
Jet air mixing system malfunction (restriction or leakage in air passage)
Inadequate fuel pressure
Pressure regulator malfunction (integrated in fuel pump)
Fuel injector (FP1) (RP1) is clogged.
Open or short in fuel injector (FP1) (RP1) control signal circuit
Restriction in exhaust system
Purge solenoid valve malfunction (stuck open)
Improper air/fuel ratio control (abnormal ECT signal to PCM)
Erratic signal form eccentric shaft position sensor
MAF sensor contamination (abnormal signal to PCM)
MAF sensor improper installation
Low engine compression
Engine internal malfunction
Abnormal engine oil condition (viscosity, deterioration)
Low oil pressure
Excessive fuel pressure
Air mixed in oil line
Metering oil pump malfunction
Leakage or clogging in oil pipe
Leakage or clogging in oil nozzle
Starting system malfunction
Spark leakage from high-tension leads
Spark plug malfunction
04-09-2013, 03:41 PM
#7
04-09-2013, 03:51 PM
#8
Title sums it all up. My car starts okay enough when it's cold, but after it's been nice and warmed up, I have to spend 10-20 seconds cranking waiting for it to turnover. I just replaced the Spark plugs/wires/coils, then went and had the compression tested, and while I'm not at minimums, I'm not at maximum levels either. What else has the potential to cause this? What else can I check?
it runs great, smooth, power is good, but not in the top 1%. cold starts aren't great, hot starts are worse.
i put the upgrade starter in it, and problem is gone....
04-09-2013, 04:27 PM
#9
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
Here's the email I got from the dealership -
Unfortunately I'm no longer under warranty. Should I go forward with replacing the engine? Or should I have them test the starter instead?
Yesterday when we did the compression check we came up with these numbers:
Rotor #1 - 7.3, 7.2, 7.2 psi / Rotor #2 - 7.8, 7.9, 7.9
Today after a short drive and an extended idle we ran test again and the readings did go down a little:
Rotor #1 - 7.1, 6.9, 7.0 psi / Rotor #2 - 7.7, 7.7, 7.8
The point at which Mazda would send us a new engine if under warranty is 6.9 on any reading for either rotor.
A new engine is 8.5 psi
Rotor #1 - 7.3, 7.2, 7.2 psi / Rotor #2 - 7.8, 7.9, 7.9
Today after a short drive and an extended idle we ran test again and the readings did go down a little:
Rotor #1 - 7.1, 6.9, 7.0 psi / Rotor #2 - 7.7, 7.7, 7.8
The point at which Mazda would send us a new engine if under warranty is 6.9 on any reading for either rotor.
A new engine is 8.5 psi
04-10-2013, 12:57 AM
#11
As 9krpmrx8 mentioned you will need RPM numbers, if they cannot provide the RPMs they should do a retest for you.
Here is a graph showing Compression/RPM. (A) Standard, (B) Minimum
Here is a graph showing Compression/RPM. (A) Standard, (B) Minimum
Last edited by Mr.Mango; 04-10-2013 at 01:03 AM.
04-10-2013, 06:40 AM
#13
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
It's a 2004. Only has around 70k miles on it (I barely drive it). They are telling me over $4,000 to replace the engine, so I'm going to shop around and hopefully find somewhere in the area that can do it far cheaper!
04-10-2013, 07:20 AM
#14
New Member
Join Date: Oct 2012
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
had the same issue last month with my sons 04 put the latest upgraded starter on it and its starts right up when its hot now. Beware the latest greatest starter is 400 bucks at the dealer.Its an easy install you can do it in a hour.
04-10-2013, 07:53 AM
#16
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
This guy - http://www.carid.com/2008-mazda-rx-8...r-9436332.html - perhaps?
Last edited by marvin_rock; 04-10-2013 at 08:05 AM.
04-10-2013, 12:01 PM
#17
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
"As far as a full blown printout, there isn't one. A compression test is done with a gauge stuck in the sparkplug hole while the engine is cranked by another tech the RPM range is around 750. A compression test is not very scientific but it is accurate.
The starter sounds strong, we have no reason to think the starter is bad."
04-10-2013, 12:13 PM
#19
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes
on
110 Posts
Uh, yeah, the guy is just blowing smoke your way. A stellar perfect starter will only crank the engine to ~300rpm. I think 310 was the highest I have seen mentioned.
He probably doesn't even know anything about how one is done, or that there is a specific rotary compression tester used. The dealer clearly has one since they gave you independant numbers, just the service manager is an idiot, or ignorant, or both.
He probably doesn't even know anything about how one is done, or that there is a specific rotary compression tester used. The dealer clearly has one since they gave you independant numbers, just the service manager is an idiot, or ignorant, or both.
04-10-2013, 12:40 PM
#21
04-10-2013, 01:04 PM
#22
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
04-10-2013, 01:22 PM
#23
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
Anybody watch House? We are about to have a House moment. Everybody lies, even if not always on purpose.
For the past 8 years, I've put mid-grade in my car. I was broke back when I bought it, but I can handle the extra $0.10 a gallon now. With all that said, what are the odds that updating the starter, updating to premium fuel will get me another 10,000 miles (possibly update the battery, but I don't think it has any issues)? I have none of the other symptoms of low compression, and all the other 5 spots seemed to read fine. Thoughts?
For the past 8 years, I've put mid-grade in my car. I was broke back when I bought it, but I can handle the extra $0.10 a gallon now. With all that said, what are the odds that updating the starter, updating to premium fuel will get me another 10,000 miles (possibly update the battery, but I don't think it has any issues)? I have none of the other symptoms of low compression, and all the other 5 spots seemed to read fine. Thoughts?
04-10-2013, 01:25 PM
#24
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes
on
110 Posts
I think you might have a misconception of what octane is, and what it does.
87 vs 89 vs 91 vs 93 octane has nothing to do with engine lifespan EXCEPT if you get octane that is too low and it detonates and destroys your motor in a single event.
Increasing your octane choice won't affect your engine's life expectancy if it runs fine on a given grade right now.
87 vs 89 vs 91 vs 93 octane has nothing to do with engine lifespan EXCEPT if you get octane that is too low and it detonates and destroys your motor in a single event.
Increasing your octane choice won't affect your engine's life expectancy if it runs fine on a given grade right now.
04-10-2013, 01:38 PM
#25
L8 BLOOMER
Thread Starter
Join Date: Oct 2005
Location: Virginia Beach, VA
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
I think you might have a misconception of what octane is, and what it does.
87 vs 89 vs 91 vs 93 octane has nothing to do with engine lifespan EXCEPT if you get octane that is too low and it detonates and destroys your motor in a single event.
Increasing your octane choice won't affect your engine's life expectancy if it runs fine on a given grade right now.
87 vs 89 vs 91 vs 93 octane has nothing to do with engine lifespan EXCEPT if you get octane that is too low and it detonates and destroys your motor in a single event.
Increasing your octane choice won't affect your engine's life expectancy if it runs fine on a given grade right now.