Chasing the 2200 rpm ping (2.7)

Oven cleaner may be the way to go. I've used Purple Power and scrubbed a good bit, but the runners are hard to get into. I may go out and rinse that out and spray oven cleaner and let it sit overnight.

 

Yes, oven cleaner will break down grease. I used it on an intake. It took several shots to get it completely clean.

Oven cleaner is a very strong base and it will react with aluminum, but it just left a slight discoloration on the intake I used it on, like on the mating surface. I didn't spray much on the exterior though.

I've hear the Berryman B12 carb cleaner will break down the grease and clean it well if you don't want to use oven cleaner on the aluminum. I only read about this after I did the cleaning.

 

Thanks for the response. I have a 15 year old gallon of Berryman from when I rebuilt a carb on my old Mazda truck. I just let the upper part of the intake soak last night in Purple Power, so I didn't use oven cleaner yet. I'm contemplating not even pulling the lower intake off because it's nothing but runners(no ports etc). I'm starting to think that the whole head has to come off which I'm seeing is a lot bigger job than it was on my old Mazda. I still may try the a dealer that does some kind of super combustion chamber cleaning.

Pinging. I really don't think I've found anything that will help eliminate the pinging. At this point, I have two theories:

1. #1 and #3 injector are slightly clogged causing a lean condition in those 2 cylinders. Kind of weird that the truck idles perfect and runs smooth with no CEL's

2. Carbon build up in the combustion chamber causing higher compression. Does my compression seem a bit high? 185, 180, 185, 200?

I'm a bit surprised that no one has commented on the compression results or the spark plug photos. I even started a thread cause I'm feeling that most folks are bored with this one and I've got nothing from anyone. Am I posting in a way that is turning folks away?

https://www.tacomaworld.com/threads/compression-test-and-spark-plug-analysis.520186/

 

I went ahead and pulled the lower intake plenum and... Holy sludgefest Batman.
Here's #1 and #2.

 

Here's #3 and #4.


But the worst is #4.

 

Damn you hats a lot of carbon build up! Cleaning all the junk out should make a noticeable difference. While you have it apart, you should really consider also having your injectors cleaned and flow tested or just buying a set of pink tops to replace them.

 

I totally agree about the injectors. I'm leaning toward pulling the head to clean the combustion chambers too since I'm half way there. It seems all I need is a head gasket and timing chain gasket, right? I already have the intake gaskets.

 

The head gasket extends over the timing gears/chain, so it's all one piece. You may need a gasket for the timing chain tensioner. If you got new injectors there are some o-rings and grommets that need to be replaced. Maybe new injectors would come with those parts depending on where you got them.

I don't think anyone gave up on your thread. Just out of ideas.

 

in my experience purple power @ 100% discolors aluminum.

 

Thanks for the response. After sleeping on it, I'm not sure about pulling the head. Doing so would really turn this into a much bigger job. Maybe the HUGE amount of build up in the bottom of the runners is causing the pinging, or an injector issue. Maybe I'll get in there and clean the build up out best I can, vacuum it out, gets some injector refurbs and button it all back up and hope for the best.

Downfall is if I still have pinging, the next step is pulling the head.... I guess. I guess it boils down to if I think the problem is more likely due to the huge amount of buildup in the runners (or clogges injectors) or build up in the combustion chambers.

Thanks for the input. I discovered that scraping the big stuff off and then spray degreaser, scrubbing with wire brush/long bristle brush and then pressure washer worked pretty well.

 

BTW, are "pink tops" just standard Beck/Arnley injectors that run ~$60/ea?

 

I honestly don’t know. They are the stock injectors that came in the newer 01-04 3rz motors. You can get them on eBay for around $100 for all 4. They are about 10% higher flow rate than the brown tops you’re using and have a better spray pattern to help evenly distribute the fuel into the cylinders

 

I like the idea of a little extra flow rate/distribution and I see some on Ebay for around that price but they seem to have the Cali numbers (23209-79135 or 23209-79080). I suppose they will work, but likely have a lower flow rate than std/fed injectors.

 

One more thing about the pink tops; aren't they taller which would cause issues with the bolts on the fuel rails?

 

With the amount of build up in the intake ports, I'd think it's very possibly carbon build up on top of the pistons that's contributing to higher compression and thus your pinging issue.
I've never gone the seafoam route for cleaning the carbon off the pistons, but it seems folks let the seafoam sit in the combustion chambers overnight or for a few hours. Not sure if you've tried letting it sit that long.

 

Thanks for sharing your opinion. I've pulled Seafoam into the intake through a vacuum hose and let it sit for 10-15 minutes but that's it.

 

Another thought, use a borescope or similar through a sparkplug hole to get a look at the tops of the pistons. If you don't have a way to get your hands on a borescope, perhaps one of those mini USB endoscope things would work? I've never used one of those so I couldn't give my opinion on it. I just know I've seen them online for 10-15 bucks, IIRC.

 

out of curiosity... how does the EGR port look and does it have a passage that distributes the gas or does it just dump it in one spot?

 

It seems plausible that the carbon build up in the intake could cause an uneven amount of air to each cylinder. It could cause some cylinders to run lean, but I'm not sure how the feedback system from the O2 sensors would handle this. Maybe some would just run rich while others are at correct air-fuel ratio.

 

Thats an awesome idea. I'm doing this.

EGR port has some build up in it but not bad at all. EGR valve dumps into a side port at the beginning of the intake manifold. You can see the build up on the left side of the intake port in the pic below(this is where the EGR dumps in).

That makes sense to me and is helping me understand how all this stuff works. I appreciate you sharing your thoughts.