inflatablepets

I have a S5 GTU with a 50,000 mile Mazda reman S4 block and I changed the oil last weekend. I put the usual Castrol 20w50 and the Purolater filter in. I drove the car for about 700 miles this week and last night I fueled up and checked the oil (I always check the oil when I get gas) and the oil smelled gassy. It also was just slightly over the full mark. The car runs very well, I get 25 MPG,, I also run 200:1 premix oil in the fuel. I still have the MOP hooked up. The extra oil is just a safety measure. The car always starts right up, but once in a while the car won't idle quite right. It's somtimes surges just a little and slightly rough. I searched last night and olny saw this issue come up for the FD. It seems that this is pretty normal for those. I never heard anything about this problem on the FC. I wonder if the problem is normal, or if my fuel injectors leak slightly, if my compression might be a little on the low side or if the injector seals are dried up. I hate to say this, but I know I need to check the compression and find out. Now that I think of it, Those miles I put on the car last week were prettymuch at or above 80 -100 MPH.

Icemark

it is normal if your injectors leak, or if the side seals are starting to go, or if you have flooded the engine, or you have a bad or incorrectly hooked up PCV (Purge Control Valve).

inflatablepets

I was thinkig the injectors might be leaking a little. The car starts right up. It doesent't act flooded at all. How would I know about the side seals? By that I mean what are the signs? I'll have to check on the Purge Control Valve. Thanks Mark.

inflatablepets

PCV works fine.

Icemark

Well the next step would be a compression check

inflatablepets

I'm going to do the compression check tomarrow. As far as the fuel injectors I have two other sets of them and I was going to send one set in to have them cleaned and blueprinted. I think it was Cruzin Performance or somthing like that is where I'm going to send them. Thanks again, I really appreciate your help.

inflatablepets

Compression is 120 per face on both rotors. I guess a bit of oil dillution is normal.

uRizen

iTrader: (2)

Does the car give you a nice cloud of smoke when you let it sit for a few days w/o running? Mine did that when I first got it, ran fine day to day, no flooding, but if it sat it would flood out. Found out it's my injectors leaking. I have a new set being sent out to Cruzin' by a very nice forum member I bought them off of, and hopefully will have a smooth running FC again when I get a hold of them.

WAYNE88N/A

I've been getting a little of this ever since I started premixing. In a perfect world, we would like like just enough premix to lubricate, with none left over after the combustion stroke. Premix (from what I've read) is designed to linger after combustion, so there will always be "extra" that seems to get forced past the side seals & oil control rings during the next compression & combustion stroke, and on and on. Actually I see it as a good thing- excess premix means that there is adequate lubrication where we need it, and have found that reducing the amount of premix (the ratio) reduces the "blowby".

I deal with by performing more frequent oil changes. If you're not running premix, and still getting gas in the oil, somehow the fuel is not being scheduled efficiently (also keep in mind we run rich in even the best of circumstances)...Before I started premixing, I don't remember having any noticeable fuel in the oil (smell), so I doubt it's "normal" on an otherwise healthy engine.

inflatablepets

I saw a small puff of smoke once. I was thinking on sending a set of my injectors to Cruzin performance since I have a bit of a weird idle. I figured it was from the wrong engine being in the car. I don't think the car floods though. Thank you.

inflatablepets

Premixing hmm... I do that. I still have the S5 MOP hooked up so I mix 1 oz or so per every two gallons of fuel. I am not sure about a fuel problem since I get about 24 mpg. I guess I should send my other set of injectors in and have em cleaned. I also changed the spark plugs today. The trailng side were carboned slightly and the leading ones looked good, just worn a bit. Which brings me to another question. How often do you guys change the plugs on these cars.
Thanks Wayne.

WAYNE88N/A

I've heard of some guys here changing them every other oil change, or about 6,000 miles, I guess. I do mine about every 10,000-15,000...

inflatablepets

Mine have about 5000 on them I think. There was a new set of them when I bought the car. The previous owner changed the plugs and couldn't figure out that there was no compression on the rear rotor.