MaxSteel21

Hello and good day to everyone. I wanted to ask if anyone here has had an issue or experience rather with the coolant bypass hose that's located under the intake manifold on a 2005 es330? I'm wondering if this is a diy job or should I pay a mechanic $400 to do the repair.
I'm not a certified mechanic however I'm pretty knowledgeable about basic things such as replacing alternators , starters thermostats etc.
From what I gather there's quite a bit of parts that have to be removed in order to access this hose that in my opinion is just a terrible design.
If anyone has a diagram or can guide me in the steps that are needed to complete this task I would greatly appreciate it and be forever grateful.
Thanks.

JacobsDad

It's not a difficult task to accomplish. There aren't very many pieces which have to be removed from the engine however, thare are many pieces which have to be disconnected to remove the intake manifold. No biggie. The hoses are pre-formed and kinda lead themselves to the spot where they need to go. The wire harness connectors can't be connected onto something they're not supposed to attach onto.

If you remove the throttle body from the vehicle, you'll have to deal with filling the coolant system. And also (after everything's back together) you'll have to let the engine idle for a few minutes while the computer adjusts engine rpm to the correct idle speed. I usually just pull the throttle body from the manifold and leave it with the car so I don't have to deal with the coolant nor the idle.

Arsenii

Hello,

Here is a thread showing some detailed pictures of the process. While the process itself is not complicated, it just involves a lot of parts to be removed, so make sure to reserve about a day, and better weekends for that to make sure you won't end up stranded. You will also need Intake manifold gaskets and OEM FIPG, Part Number is 00295-00103. Here is a good place for aftermarket parts.

Depending on the mileage and service history, it may be a very good time to also swap out the Spark Plugs and Valve Cover Gaskets that tend to leak as well, since they will be in direct access when the manifold is off, and while the coolant is drained, you may also replace the thermostat, just for peace of mind, there is no particular reason for it if it works. Make sure to only use OEM thermostat though, aftermarket ones tend to cause more issues than benefits in the long run. P/N: 90916-03129 for the thermostat; 16325-62010 for the gasket

If the mileage is above 160,000-ish miles, it may be beneficial to also replace the wiring for the Knock Sensors (P/N: 82219-48010), which tends to get cooked with all the heat in the engine bay during the lifetime of the car, which may save you another trip there.


Hope this helps and best of luck!

MaxSteel21

Thanks JacobsDad and Arsenii for the replies I appreciate it so much. I ordered the bypass hose and intake manifold gaskets earlier this month and they arrived yesterday. The vehicle has over 200k miles so thanks for the advice on valve cover gaskets and knock sensor parts .
I do have a second vehicle to drive so I won't be in a hurry to try and complete the job.
Definitely going to be a weekend task.
Again thank both of you guys for your valuable information and I will post the progress with pictures when I get started.

das1960

From experience -- ratcheting box wrenches in 12mm & 14mm are incredibly useful for the bolts behind the intake manifold.

MaxSteel21

I finally got around to replacing the coolant bypass hose under the intake manifold last weekend. Everything went well until I it was time to remove the bolts at the back of the plenum. You definitely have to have box rachet wrenches with the pivoting heads in order to remove them. It's such a tight spot which took me about an hour to get them off. The knock sensor wire harness was in very good condition. So I didn't replace it. Since I had access to the rear valve cover I proceeded to replace the gaskets. Pretty simple job overall just took my time and I saved $400 bucks doing the job myself.
Thank you guys for the valuable input... Much appreciated