I just got a compression test from one of the members yesterday. I have low compression on the front rotor (just below minimum) and the rear rotor is fine.

Im trying to figure out what to do. If i should try to get a new engine from mazda (i still have warranty) ?? If i should just keep driving it till the rear rotor fails minimum as well and then get a new engine from mazda ?? What can i do to "increase" or minimize loss of compression ??

Here were the results:

F: 89.5 / 91.6 / 100.9
R: 103.5 / 103.5 / 102.5

This is normalized to 250rpm. this is in PSI i believe


The car starts up fine and drives fine but i sort of feel a power loss and it feels like it takes longer to get up to redline.

I also need to replace my spark plugs i have one that is toast.

 

Get a reman under warranty or get a well built engine from a reputable builder.

 

Will mazda honor the warranty even though ONLY ONE of the rotors is below minimum ?? Or do both rotors have to fail ??

 

The only way you can "recover" lost compression is if the compression lost is caused by the seals not seating properly due to carbon, in which case clearing the carbon MIGHT restore some of your lost compression.

Otherwise, there isn't any way to restore it without a rebuild.


But, replace the plugs at least.... you will need to do that anyway.

 

All you need is 1 of the 6 numbers below spec, OR the difference from one rotor face to the next greater than the minimum. (21 psi). So you can technically have all 6 faces above spec, and if there is a pair with a differential of more than the allowed range, it is still classified as failing.

 

will do thanks. Ill give it a seafoam and replace the plugs.


Umm in terms of driving style. Should i still drive spiritedly keeping the revs up there ?? or should i take it easy from now on ??

Im assuming the spirited driving will actually help the compression from going any lower

 

Heh

That is a hard one to answer. Depends on the reason for the compression loss, and we don't really know what that reason is.

Hard driving will make it worse if it's a side seal problem, better if it's a carbon problem.
Keeping the engine 'calm' will make it worse if it's a carbon problem, and have no impact if it's a side seal problem.

If it's a warped housing, then nothing you do either way will really make much of a difference.



My gut tells me that it's a carbon problem though. I'd really recommend just changing the plugs, decarbing, and seeing what changes.

 

^ oh man here come the headaches.

My best bet would probably do a mix with taking it easy and redlining every so often.

I will get a seafoam done and spark plug change and then try to get another test.

Thanks

 

This is how you should drive normally anyway

Too much low = carbon, too much high = side seal/heatspotting/warping. Can't just sit in the middle either. Oscillate between them as appropriate.

 

Alright thanks for the help.


I was about to toss in the towel and try to get a new engine but it seems like there might be hope.

 

Umm if your below min compression and have a warranty, why not just go get a new engine? It's like 100 bucks a try...

 

I don't mean to hijack, but I have a question: if one does need a replacement engine, and it's covered under warranty, is accepting the replacement from Mazda the only option? If you wanted to get a replacement from someone like Mazmart, would Mazda cover that, too?

 

Legally, yes, they could cover it if the circumstances are right. For example, you had your engine replaced out of pocket and then they offered reimbursement (think the clutch pedal assembly issue. The letter notes that if you fixed it out of pocket, you can request a reimbursement). However, they are pretty much going to insist you take their reman, since it costs them far less than reimbursing you retail price for someone else's engine. (I'd guess the actual parts "at cost" is under $1,500 for a reman from Mazda's point of view, though they still pay ~$90 an hour or something for the labor to install it)

 

Nope, they will only cover replacements done through their dealership network\mazda products.
That's why getting a reman is pointless. Fork out the cash and get a good engine!

 

PAYING for a reman is pointless. Getting a free reman certainly has a point

My replacement cost me $54, for belts. Even if it only lasts 20-30k, there is still certainly value in getting that reman.

 

You can get one on your own from Mazmart, but they won't reemburse you for the cost. And If that one also goes bad, it will not be under the Mazda warranty.

 

Well i guess that's a good reason... it gives you a bit more time to save money for an even better build. Given the quality of mazda remans that's the only reason i can think of.

 

Entirely agree with that

 

Definitely do the free re-man from Mazda.
while the engine is out you can spend a little money on some replacement parts that are far less expensive to install when there is no engine in there.
updated motor mounts.....updated SSV valve......maybe new omp lines/nozzles......

 

Okay so i guess i should try to put some money asside to get the compression test by mazda and then go from there.

In the mean time do you guys think its worth spending the money to seafoam it .. changing my plugs etc etc when i know i will get the engine replaced by mazda eventually

 

If you are going to seafoam, do it before changing your plugs, as it can foul your plugs quite a bit. Otherwise, replace the plugs before taking it to the dealer, as they could insist you pay their price for plugs. And you need new plugs anyway.

 

ive been thinking about this all day yesterday. Because i winter drive my car, do you guys think it would be wise to drive the car with low compression for another summer/winter and then come spring 2013 get the engine replaced ? That way i wont have to make the new engine go through the harsh winter right after getting it ? The spark plugs will be replaced soon though.

What do you guys think ? Is it okay to drive the way with low compression on the front rotor till next year ??

 

Why not get it replaced right away? Depending what is causing low compression it could get really bad all of a sudden and leave you stranded somewhere in the middle of the winter. You might get lucky and only get the hard starts and have to wait 15-30 minutes to be able to start your car after shutting it off.

Also what year is your car? If its an earlier year and you don't know exactly when it was first purchased your warranty could be very close to ending.

 

Why put off until tomorrow what you can have done today?

The longer you drive the car in its current partially failed state, the more likely you are to cause damage to other parts, like the catalytic convertor, and those new coils you installed.

You already know the engine has an issue today, that would result in the dealer replacing it for free. Why are you even asking these questions?

And on that note, you've been a member here for how long now?
Why are you asking these questions? You should have already figured out what your plan would be over 2k posts ago in the event of this very situation.

I bought my car brand new over a year ago.
I knew within hours of reading the forum before buying the car that if I ever though there was a chance the engine would need to be replaced under warranty, I wasn't even going to think about it, and hand the car over for testing.

I've never understood why members of the forum who think there's a chance their car might fail a compression test while still covered by the warranty, wouldn't want to bring it in and have the test done.

BC.

 

Car is 2006 with about 92,000km which is about 56,000 miles i think.



Ya youre right i should just get it fixed as soon as i can over the summer. Well one of my plugs is toast so ill probably have to get that replaced as well.

Thanks