Trouble After Working On Water Bypass Pipe [SOLVED]

TacomaWorld I need some help...you're my only hope.

The plastic water bypass pipe on my 2007 2.7L Tacoma developed at bad leak.

So, lastnight I changed it out with a friend. It was so bad that the nipple on the top of the back of the pipe (towards the firewall) snapped off in the hose. We had to dig it out.

We replaced the corroded plastic pipe with the new all metal one and new metal gasket. The job went fairly smooth and took maybe two hours.

We got everything hooked back up, refill the coolant we had drained and started the truck. It idled fine...at first...the longer it ran the rougher the idle became until the engine eventually choked out.

The check engine light came on. My friend used the code reader. Unfortunately, my buddy read the codes (we didn't write any down) and then cleared them. I can't tell you what they were. He typed a code in on this phone and pulled up a YouTube video from someone with an X-Runner who cleaned their throttle body to fix the rough idle and code.

Not much help I know and I appologize...

So, we figured we did something wrong or didn't get something connected. We came back this morning and essentially redid the entire job.

Disconnected everything, took the intake manifold back off and this time changed the intake manifold gasket.

We took our time bolting everything back on ensuring, all wire harnesses and all hoses we connected.

Guess what...

The same thing happened. The truck started fine. It idled fine. Well...for the first few minutes. After awhile the idle dropped to about 500rpm then got rougher until eventually the engine choked/stalled.

We thought maybe it needed to drive for the computer to relearn the appropriate idle and fuel/air mixture.

Nope.

I tried to drive...if my foot wasn't actively on the accelerator the rpm would drop and the truck would stall. It took a lot of revving the engine in neutral to keep it from totally stalling to limp it home.

This time, it's not throwing any engine codes.

I've combed over everything I don't know what's causing the issue...

So please fellow TacomaWorld-ers help. Has anyone else had this issue after replacing the water bypass pipe (ie removing the intake manifold).

 

Anyone have ideas or had this issue?

Update: I found another post on TacomaWorld from Alphazulu21 with what appears to be exactly what I'm experiencing.

The only diffrence is my #3 ventilation hose is currently attached. It seems to have an elbow in it. I'm wondering if I could have broken the elbow and damaged the hose.

When we pulled the intake manifold off the first time, I have no idea if the hose was on or off or halfway. We changed the pipe without full pulling the intake manifold off and out.

The second time we actually fully took the manifold off and out. I had searched around and I made sure to attach the hose.

https://youtu.be/LuDR91TfDMQ

 

Sounds like you've got a vacuum leak somewhere. Can't really help much more than that. Triple check everything you touched to do the job, if you cracked the elbow it's gonna suck in air and mess shit up

 

Thanks TYetti. I've got it taken apart again. I found some dry rot on the ventilation hose so I'm going to replace it...

 

Update: I cleaned the throttle body and replaced the throttle body gasket...now I have a working truck!

Shout-out to Centennial Toyota's Service Department for the recommendation.

...stupid plastic water bypass pipe...

 

I own a 2006 and need to get this done, if for nothing else my peace of mind. My luck, I will be on a long trip in the middle of winter at -33 degrees with the wind chill and find myself with an undrivable truck or worse yet be on that long trip and not notice the coolant leak until my engine blows up. I would like to have words with the Toyota engineers that made the decision by cheaping-out on a part that so crucial.

 

Getting this plastic pipe out early would be a good call. My leak started with a few drops of coolant and about three weeks later...I was losing a full coolant reservoir tank overnight.