Newbie here.. Just a couple questions.

Technical Discussions - Got a mechanical problem?

Moderator: bajabob

Post Reply
GrandpasBaja
Scoobytruck Lurker
Posts: 5
Joined: Thu Sep 15, 2016 8:35 am

Newbie here.. Just a couple questions.

Post by GrandpasBaja »

Hello everyone, sorry for the long post. I just bought an automatic '06 Baja from my grandpa in March this year. Mileage is currently 103xxx. Lately, I've been noticing a slight power drop / shifting fluctuations when I get between the 30 - 40 mph range. Not showing any CELs. If the rpms aren't up high enough, it seems as if the truck is shifting hard, then the rpms drop about 500. Now, I did have the timing belt replaced recently and the mechanic said there was a very minor oil leak coming from the head gaskets. I thought it may be a compression issue? I also thought it might be the tranny, so I changed the fluid out. Didn't notice any difference, but I did not change the tranny filter because it seemed like it was stuck. I've also changed the spark plugs and spark plug wires. No difference there either.. Someone I know said it may be a throttle position sensor? I'm just stumped atm, gonna try to get a computer hooked up later this week. Any thoughts would be appreciated. Thanks in advance everyone!
Acro2pilot
Scoobytruck Master
Posts: 227
Joined: Fri Sep 07, 2012 5:39 am

Re: Newbie here.. Just a couple questions.

Post by Acro2pilot »

Turbo or non turbo?
GrandpasBaja
Scoobytruck Lurker
Posts: 5
Joined: Thu Sep 15, 2016 8:35 am

Re: Newbie here.. Just a couple questions.

Post by GrandpasBaja »

Sadly, it's a non turbo.
Acro2pilot
Scoobytruck Master
Posts: 227
Joined: Fri Sep 07, 2012 5:39 am

Re: Newbie here.. Just a couple questions.

Post by Acro2pilot »

I wouldn't go right for a compression issue, if you had a head gasket issue that bad you would have some big issues like overheating, fluids mixing and it would likely look like an oversized vape going down the road. You can confirm compression as well as ring and valve health with a compression and leakdown test but I would put that further down your list.

A more likely source of you oil leaks, which is easily confused with the head gasket, are the cam cover seals. If you look at the cyl head you will see where the head joins the block, and if you look further away from the center of the engine you will see a second similar looking line that is where the cam cover goes on to hold the cams in place, with the valve cover bolting onto it. That seal can leak and it can easily look like it is coming from the head gasket. Fairly easy to clean from below and then look for fresh leaking to find the source. If the cam covers are leaking they are easier, faster, and cheaper than head gaskets to deal with.

Two things that might not trip codes but can cause stumbling and other driveability issues are a dirty Idle Air Control valve (IAC) and an aging 02 sensor (the front one). Cleaning the IAC is easy and I would do that first then take it for a drive. You didn't say if you were having idle issues but this can cause issues off-idle if it is sticking and is a very common and overlooked maintenance need. Found a good how to for you: https://www.youtube.com/watch?v=cvE0L9g4PbQ The 02 sensor, best to get an OEM one, will cause bucking and surging which can feel like shift issues in an auto. TPS could be an issue but I would do some more troubleshooting first.

One other easy check is the coil pack the plug wires plug into, those terminals can corrode and give you all sorts of fun issues. Pull the plug wires and make sure the terminals are clean.

Obviously do check for codes and pending codes no matter what the CEL is doing, let us know what you find. One suggestion is to get an ELM327 or similar wireless OBDII reader and an app called Torque, not only can you check and clear codes you can pick data streams and watch what sensors like the TPS are doing at the moment the problem occurs, a must have tool at under $20 for both.

Regarding the tranny, are you talking about the spin on external filter?
GrandpasBaja
Scoobytruck Lurker
Posts: 5
Joined: Thu Sep 15, 2016 8:35 am

Re: Newbie here.. Just a couple questions.

Post by GrandpasBaja »

Hi Acro,
First off, thanks for your detailed response and link. Oversized vape :lol:. I'll start with that idle air control valve cleaning on Friday and see if that helps. Too many different sensors and valves on cars.

Yes I was talking about the black screw on filter next to the drain plug. I read afterwards that it should be a maintenance free item? He lived on the highway so I thought he may have stretched the transmission bands out.. I do mostly city driving. Seems to shift a little better when you punch into the accelerator.

Also sometimes starting off while at a stoplight I feel a pop coming from around the gas pedal area.. Not sure if that would be related? Thank you again sir for your help :mrgreen:. Lovin' the lifted look on your 2.0 btw.
Acro2pilot
Scoobytruck Master
Posts: 227
Joined: Fri Sep 07, 2012 5:39 am

Re: Newbie here.. Just a couple questions.

Post by Acro2pilot »

Opinions vary on that filter, I consider is part of my annual service, regardless of how many or how few miles every year I change engine oil/filter, trans oil/ filter, diff fluids, brake fluid, and coolant. I do that on every car i own but obviously more frequent oil changes on my daily driver. It is a practice I picked up in exotic cars. You can go through those systems 5-10-15-20 years later and rarely is there contamination, scale, corrosion, and seals tend to stay fresh. I advocate for that practice, and the cheaper the car the cheaper insurance it becomes.

As for the pop, could be allot of things, although it is higher up take a look at your pitch rod under and behind the air plenum, probably not bad on yours but take a look.
GrandpasBaja
Scoobytruck Lurker
Posts: 5
Joined: Thu Sep 15, 2016 8:35 am

Re: Newbie here.. Just a couple questions.

Post by GrandpasBaja »

Okay, I'll take a look to see if I can find the pitch rod. Thanks for the help man, I'll let everyone know when I'm able to sort these issues out. I'm meticulous about my vehicles so anytime there are odd noises or sounds, I'll take it to my mechanic.

Been getting adventurous with the Subie though, doing the tranny fluid change and valve cover gaskets. I usually never even change the oil myself, lol.

Found out saving money and learning > hoping that someone else will do the job right. Even if I screw it up in the process :roll:.
GrandpasBaja
Scoobytruck Lurker
Posts: 5
Joined: Thu Sep 15, 2016 8:35 am

Re: Newbie here.. Just a couple questions.

Post by GrandpasBaja »

One more question Acro, does that external screw on tranny filter have a bolt holding it in or should it just twist off? Thanks 8)
Acro2pilot
Scoobytruck Master
Posts: 227
Joined: Fri Sep 07, 2012 5:39 am

Re: Newbie here.. Just a couple questions.

Post by Acro2pilot »

Subarus are very user friendly on maintenance, a great brand to learn on. Pics would help confirm I am pointing you at the right filter, but the round external one spins on and off like an engine oil filter. Mine was pretty tight as well.

And that pitch rod, it looks like a dog's bone and connects the firewall to the engine so the engine cannot pitch back.
Post Reply