DIY: 2005 XC90 2.5T Throttle Body Cleaning Topic is solved

[Smbray1986]

So I was able to get the throttle body out wasn't too hard just took time finding the right socket size. Thought it would be a 7mm or 8mm but it was actually a 10. Anyways got the carb cleaner and made it look almost brand new. It was disgusting and had clearly not been clean in a long time or ever. Also purchased a new gasket (could putting the gasket on backwards cause an issue?) Put it all back in, started it up and same issue. Except this time not only is pulling code p2111 but also p0102. It still idles rough and rpms bounce a but around 1 (sorry not that savvy with proper names lol) my husband pressed the gas and for a moment it seemed to quiet down then right back to rough idle. And the smell was like gas oil acetone (maybe from the carb cleaner?) Any insight with this new information?

[chitownV]

I don't remember the gasket being directional. As long as you tightened the throttle body evenly, it shouldn't be a problem.

What happens if you unplug the MAF? Did you try to clear the codes to see what comes back? Have you ensured all the intake boots/tubes are tight and not leaking air? One know place is the rubber part that goes from the tube running over the engine down to the front passenger side intercooler inlet (by the radiator). Oil on the boots, close to the connections, can indicate leaking air.

At 160k miles, it wouldn't be out of the ordinary if a throttle body needs to be replaced with a lower mileage one. Not knowing the history of your XC90 or its current state, it is completely acceptable an issue like this can occur and there could be more than one normal issue at that high mileage.

[Smbray1986]

I dont know why I cant see my last two responses but I'll try to remember my response. I'm not sure what you mean by what happens when MAF is removed? Is that the electrical unit that plugs into the throttle?? If so I removed it to clean throttle but that's it should we unplug it and see how the car runs? And did I mention is threw up a new code of p0102?? And here's a picture of the hose you mentioned. It's pretty gnarly but my husband says it's on tight (but who knows)

[chitownV]

Yeah, that hose could have a crack in it leaking all that oil, especially suspect that it’s accumulating away from the end of the hose which would have indicated a loose hose clamp instead. You may need to replace that hose and the unmetered air code could be from that.

The MAF or mass airflow sensor is different and closer to the air box. If it had an issue and is the cause of rough running, sometimes unplugging it puts it into a default mode changing how the engine idles and runs, which can help determine the MAF is an issue. It is separate from the throttle body.

So, it looks like you have the next step which is a rubber intake hose. At 160k miles and 17 years, it got more than its serviceable life.

[Smbray1986]

Thank you so much! I'm hoping to get another year or two out of it but we shall see. Now that I know what the MAF is it did look good so I'm not sure the issue. I'm going to get a hose since they seem pretty affordable and easy to replace. Is that correct any insight before diving into that replacement?

i have seen some stuff about needing to reprogram the throttle computer or whatever after cleaning it or replacing it is this true? If so do you know the steps in order to do this if its needed? Or is it not? Again thank you so much.

My husband wanted me to relay a message. The day before all this happened he ran out of gas at his job. A friend of his pulled out a gas can from his truck and he did say it was regular gas not diesal. But who knows. Anyways could contaminated gas cause this issue as well? And if so could it mean the issue is the fuel pump or fuel filter?

[chitownV]

You can go into many many different "I heard" scenarios of what rough running could be. Bad gas would throw different codes than the ones you are getting. Work with what you know and right now it is evident that the intake hose is leaking. Again, there could be several issues that have accumulated over time and have gone unnoticed or not been fixed. But go with what you know right now because it is an issue regardless.

BTW, the MAF cannot be determined good just by looking at it. It sends a signal. You mentioned code P0102, which is saying the signal for the MAF is too low, or there is low air volume/mass traveling through the MAF, the only place intake air should travel through. That is why I asked about leaks, such as the intake boot as air is entering the intake from somewhere else. Also, ensure your intake air filter is clean or you need a replacement one.

Your rough running is a good example that not all P0101 or rough running may not be a dirty throttle body. Intake leaks, such as the common intake boot, should be checked first. It's easy to visually check.

[Smbray1986]

Should we replace the entire hose or just the part I showed you in the picture that has the buildup near the meet of the next section of the hose. Just looking for input

[chitownV]

Just that hose. There is another rubber hose that is less prone to brekage, but can get loose and leak at the back (by the firewall) of the engine. It's a short hose and connects the turbo to the plastic tube. The tube is plastic and it may help it unbolt and unscrew (look for torx holding screws) the tube.

For the sake of this thread topic, it might be a good idea to start a new thread with your specific issue of rough running, summarizing what you have already done, and what you plan to do.

[cn90]

- Actually that rubber hose has oil and debris collecting on the outside only. Clean it and if there is no leak,
you can keep the hose. That hose rarely fails before 200K miles.

- The throttle cleaning is a very easy job if done as posted, you won't need to reset any computer.

- I posted this DIY in Nov 2016, so far so good...

PS: To answer some questions above, the throttle housing bolts could be either 10-mm (early years) or 8-mm (later years)...

[chitownV]

I have actually changed the rubber intake boot on a 2.5t with 100k miles on it since it had a crack and showed the oil accumulation. It too had a MAF related code saying signal low (indicating low airflow through the MAF) and rough running.