2004 6spd w/ 49,000 miles. Two tone leather, sunroof, spoiler, yada-yada. Inside and out is immaculate.

Just got back from compression check (I actually listened to the advice on hundreds of these threads, and forked over the money myself):

Rotor 1 @ 206 rpm - 6.7, 6.6, 6.2 - Normalized for 250 speed - 7.65, 7.75, 7.25

Rotor 2 @ 212 rpm - 6.6, 6.7, 6.6 - Normalized for 250 speed - 7.5, 7.6, 7.5

$8,750

 

Those are passing numbers. Anyway, did you check if the engine is original or a reman?

 

The engine is original. I do understand that I will be out of warranty.

I have an old beater to drive, plus some extra money saved to buy the rebuild kit or new engine when/if it's necessary. I can do the labor myself.

On a side note, has anyone heard of decarbing making the compression worse? When the mechanic who did my compression check gave me the numbers, I replied that those numbers weren't to bad for a 04 engine that had never been decarbed. His response was "I've seen decarbing go both ways when it comes to compression".

I'm sure in his experience he has seen a car that scored less after a decarb, but I find it unlikely that there was a causational relationship. Any thoughts?

 

Look for a blue tag right behind the coils. That is the sign of a Mazda reman.

 

Yes, if the carbon buildup is helping to hold seals in place and such

 

Or on the front cover.

 

Make sure MSP-16 (a reflash) has been performed. The dealer will know based on the VIN.

 

Engine is definitely original. Seemed to pull very hard even at low RPMS (I have driven these before, but to be honest it's been awhile).

Some confusion around the MSP16 reflash. The dealer he usually takes it to confirmed that they reflashed it. The dealer I use cannot see the reflash when they pull up the VIN. I think his dealer didn't update his VIN in Mazda's system. In the end, the compression numbers, condition, and price seem right so I pulling the trigger.

Next week it goes to the dealer I'm using to reflash, even if it's just an overwrite.

I really wanted to write this post because you can spend literally 100 hours (I have), looking at "I'm thinking about buying it", and maybe find 3 posts with compression results. I thought it might be helpful for others looking for a car to give my results.

Most post go a little something like this:

"I can't wait to buy this AWESOME car! Should I?"

"Did you get a compression check? You NEED to get one"

"No"

"I can't tell you whether or not it's a good deal without the compression check"

"Okay, I'll get one tomorrow and tell you what I find"
-End of thread

I'm willing to bet money those same people bought the car, but were too embarrassed to admit they bought the car without the test.

 

Make sure it will re-start after it has been thoroughly warmed up.

 

Checked the hot-start twice. Both times it fired right up. However, I still plan on getting a stronger starter given the cranking speed is around 200.

 

Get a BHR ignition kit...

 

A replacement starter is a good idea.
Also, while normally I just recommend ignoring anything that Monchie has to say, he brings up a good point (for once).
Though his recommendation of replacing the ignition system won't actually help increase your cranking speed.

How old is the ignition system in the car you are buying?
If its original, you might want to replace the parts with new bits.

If you go with OEM, or aftermarket OEM, or Aftermarket Superior parts, that's up to you.

BC.

 

I thought I'd provide an update.

The coils/plugs/wires were changed 1500 miles ago. Oil changed every 3000 miles. The owner said he didn't have to put oil in the car that often which does concern me. However, since he owned it he only drove about 1500 miles every 4 months, so I suppose (hoping) that's what he meant by "not that often".

After reading tons of these forums, it's clear that I could easily get "paralysis by analysis". I decided to pull the trigger on this and I take possession in two days. Given this post is in the purchasing thread, end result:

2004gt (no nav) 6 speed w/ 49,000 miles
$35 per month insurance full coverage. $500 deductible
$8,750 purchase price. Financed through PenFed for 48 months @ 1.49% APR

I hope and pray this car treats me well. It seems like these engines can be luck of the draw, but I have money if a rebuild or new engine is needed. Wish me luck!