Possible piston slap, pinging, and overheating

[J-Goz]

Hey guys, long time listener first time caller. I'm having some serious problems with my 02 Outback and hoping for a little advice. I just lost my old engine to the timing belt tensioner snapping off and totally busting up the insides. I have a reconditioned EJ25 with about 2200 miles on it at this point. I did everything recommended during break-in as far as not driving at high sustained speeds, changing the oil at 1000 miles, etc, but I'm having some issues with this engine. First of all, I have a ticking sound when I start it up. I know it's normal if it goes away in a few minutes, but this can last for about 15 or 20 minutes, so it's definitely lasting after the engine has warmed up. Also, I've been noticing a stuttering sound when accelerating up hills, etc. I did a little research and found out it's a "ping" sound caused by pre-combustion due to possible excess heat. I didn't think too much of it for a little while, and then last weekend I noticed while idling that the car got dangerously close to overheating. This was after a 2 hour road trip, so that may have had something to do with it. Anyway I checked the coolant and noticed the level in the reservoir was really low. I did a full flush of the coolant and for 2 days the sound disappeared as far as I could tell. It's hard to say for sure because it's an intermittent sound anyway. I heard it again while driving today and checked the coolant. It was back to the level when I first flushed it, and there's a distinctive burning smell which I'm guessing is the coolant burning off. The thermostat is definitely working because the upper coolant hose gets hot as hell. The fans come on when I turn the AC on but I haven't noticed them come on at any other point. The check engine light is on, but it's been on since the engine was replaced. I don't have access to a scan tool, and don't know where to get a hold of one to check it out. If anyone has any possible suggestions I'd really appreciate it. I'm pretty fed up with this car at the moment. Oh, another strange thing it's been doing - sometimes when I release the accelerator for a second and then press the accelerator again, even just barely, it jerks and then gets a burst of speed.

[DarkPhoenix]

I would bring that car back to where you got the engine installed and have them look at it.

[jey]

Did you burp the system of all air when you flushed the coolant?

Any auto parts store, Autozone, etc. will scan the ECU for codes for free.

[J-Goz]

Burp the system? I don't know, I just followed all the instructions in the Haynes manual. I didn't see anything about burping the system in there.

[DarkPhoenix]

What he means by "burping" is making sure the relief "valve" is opened after filling the coolant to bleed the system. Haynes I believe has this procedure in there.

[J-Goz]

The only thing I see in the Haynes manual is after running the engine for a little while and letting it cool off, adding more coolant and squeezing the upper radiator hose to expel any air. I haven't done this yet and will try it as soon as the engine cools down.

[mike-tracy]

Here's my "technique," works every time for me:

I can't recommend getting an OEM thermostat enough - the problems with running other ones are well documented on every subaru forum I've seen. The OEM thermostat has a bleeder that lets trapped air out (from the bottom of the radiator) that most non-oem ones don't have.

Here's a couple things to get most of the air out:

Park the front of the car on ramps or on a steep hill, nose up.
Open the radiator cap AND bleeder screw.
Fill up till it can't take any more (the bleeder overflows), and fill up the overflow bottle to the full line.
Put the radiator cap back on.
Using a funnel, fill more coolant into the bleeder screw hole, put the bleeder screw back on,
and let the car warm up to operating temperature with the heater on full blast (helps draw coolant into heater core)
Turn it off, and wait for it to cool all the way, and top off the radiator again the usual way, but with the bleeder screw open to let out any last air. Let it warm up and cool down again an additional time and refill again.

This technique works for me, and is a couple extra steps from the endrench procedure (link (http://www.subaruoutback.org/forums/attachment.php?s=&postid=69004)) but I haven't had any problems since.

[DarkPhoenix]

^^That should be in the DIY, if it isn't already!

[J-Goz]

No kidding! I appreciate the advice, but I can't find the bleeder screw. It says in the link you gave that it's only on turbo models? Is this true or am I just not finding it? All I could do in the meantime was squeeze the air out of the upper radiator hose.

Also, I went to Auto Zone today and hooked up a scan tool. It came up with the codes p0128 - Coolant temp below thermostat regulating temp, P0130 - o2 sensor circuit malfunctioning (Bank 1 sensor 1). It came up with the p0128 a second time, but it said pending next to it. Since I reset the codes and took a 25 minute drive home the CEL hasn't come back on, but it was pinging A LOT along the way under slight acceleration. If the o2 sensor is faulty, would it have come back on? It could've been a code that's left over from when the engine was installed in the first place and not even be relevant.

The guy who installed the engine just said check for coolant leaks, and I'm calling the place I got the engine from to see if they have any suggestions. Fortunately the motor came with a 30,000 mile warranty on it.

Can air in the coolant be causing these problems? I can't imagine there's that much air still in it, but what do I know. I'm at a loss for now.

[jey]

Bleeder is a plastic screw at the very top of the radiator, other side from the cap. It has a + right on it for where you can put a screwdriver. Be careful, they are easy to strip (plastic).

A lot of CELs require a few drive cycles to come back, especially ones involving O2 sensors where there needs to be sufficient heat in the exhaust to detect a problem anyway. A bad O2 sensor can definitely cause pinging.

Take a look at the engine temp gauge next time you drive. Is the engine warming up as quickly as it should? If not your thermostat could be stuck open. Or the coolant temp sensor could be failing.

[J-Goz]

Thanks for the help, I really, really appreciate it. The temp gauge goes up pretty quick. I don't think it's the thermostat, but I may just replace it along with the o2 sensor. I'm also going to check the electrical connections to the fans. They only turn on when the AC is on. Today it was in the upper 80s and I ran the car for awhile, and when I stopped the fans weren't doing anything. I haven't heard them at all. So hopefully this will stop the problem. Thanks again for your help.

Oh and the CEL has already come back on. Didn't take very long.

[ShadowGT]

The right side radiator fan is the sub fan. It only comes on when the ac compressor comes on. The left fan is the primary, it comes on after the engine reaches operating temperature and stays on as long as the key remains in the accessory on position.

[J-Goz]

The right side radiator fan is the sub fan. It only comes on when the ac compressor comes on. The left fan is the primary, it comes on after the engine reaches operating temperature and stays on as long as the key remains in the accessory on position.

Ok, thanks. They are both on when the AC is on, but neither is on otherwise, so I guess there's an electrical problem there somewhere. Also, I searched for the bleeder screw, even took off the air intake and looked under there, but still no luck.

[jey]

Subarus have pretty good cooling. Even on a extremely hot day the primary fan does not come on while idling for me, only after I've out drivnig really hard. But if the temperature gauge is going way up and the fan still isn't coming on something's wrong.