Bosch throttle body questions Topic is solved

autoperdu · Post by **autoperdu** » 14 Oct 2015, 12:43

Good day to all, this is my first time posting so please excuse any faux pas. I bought a 2005 xc70 in april and have certainly enjoyed my ownership so far. Unfortunately about a month ago i started to have a stumbling at idle then finally it died in my driveway, it would crank, start then immediately die. Cleaned maf still no luck, bought new maf disconnected battery and everything was running again. Still had a stumbling idle so replaced fuel pressure sensor and camshaft position sensor, ran great for about a week then started acting up again. Had purchased a cheap obd2 reader and it was giving p0101 and p2187 codes prior to car not starting anymore.
I then took on cleaning the throttle body, removed it and noticed a rather stiff action of the throttle plate but not being sure if this was normal just kept on going until everything was clean. Also noticed that there was a gap when the throttle body was at rest. Replaced everything and hooked up battery still crank, catch then immediately dies.
I at this point tried the key in position 2 to see if i heard the throttle body test itself, nothing but a high pitched sound. Turned off key and noticed the sound for a period of time seeming to eminate from the area where the throttle body resides.
So my question is: will a failed throttle body result in the no start condition i have? I can hear the fuel pump when i turn the key so think that i am getting fuel, i apologize for being so long winded, just wanted to give as complete a picture of what i have done as possible.

Post by **oragex** » 15 Oct 2015, 11:10

The throttle body is not supposed to be an issue for the 2005 but we never know..

What is the mileage? The timing belt looks fine? An issue with it can cause a non start condition.

Battery & alternator check fine? I would also look into the gas pump and fuel filter - depending on the mileage.

autoperdu · Post by **autoperdu** » 15 Oct 2015, 12:08

Mileage is 156k give or take have changed fuel filter and can hear the fuel pump, have not checked fuel pressure as i haven't ever done that before, had replaced top engine mount 2 months ago and belt looked ok when i had covers off, but i am not a mechanic by trade and if there are some pointers to further gauge this i would greatly appreciate them.

autoperdu · Post by **autoperdu** » 03 Nov 2015, 12:44

So it has been a month of trying to figure this out while funds had to go elsewhere, took throttle body back off and then had a go at looking at timing belt.
This is what I found, it would appear that there is oil/grease on the lower timing belt area I am uploading some pics, I also noticed when I took the timing belt cover off that there seemed to be oil on the bolt holding it on. Is this an indication that I need to do the PCV?
Regardless of how this looks I do not think it is the reason for the car not to start. Am going to pull the relay for the fuel pump today or tommorrow (located underneath main fuse tray in engine compartment) to check that, is there a relay for the fuel injectors that I should check as well?
Apologies in advance for the shaky hand pics.

autoperdu · Post by **autoperdu** » 06 Nov 2015, 12:13

For anyone with a passive interest with what finally happened with this car (as of today). I reinstalled the throttle body and got everything back into place cranked with no start then a stumble and die. I probably left out an important piece of info ie: that I was getting great gas mileage to the tune of almost twice what I was getting before (had 300 miles on odometer since last fill up and it was registering at just under 1/2 tank). Well it would appear that the gauge is lying to me or something to that effect, put a gallon of fuel I had sitting around in and it started right up.
Has worked for all of 20 min that I have played with it so now the new question is does this mean that I need a new fuel pump? Is the sending unit faulty? Can I replace just that? Sorry for new tangent, will post this somewhere else if I need to.
Just wanted to say that the car is running and (for now) have ruled out throttle body.

And on a non engine note my blower motor is now not working, what should i check for that? Hoping that it is as simple as a fuse or relay...

I would also like to thank those that have taken the time to read this post and comment, it is a great resource for those not particularly raised as gearheads.

Post by **FLXC90** » 06 Nov 2015, 12:22

Okay three issues to look at.
1) Oil leak-check for a visible source, cam seals, cvvt sprockets, piston squirter bolt (near water pump), or a trail from top of engine.
2) Fuel cluster unit- yes you can get the sender separate from the pump. or replace entire unit. If you replace the whole thing, keep your pump as a spare.
3)fan motor-does it not work at all, or only on some speeds? fan motor or switch for the former, resistor for the latter

autoperdu · Post by **autoperdu** » 06 Nov 2015, 12:44

Thanks for the reply! So am pretty sure that the cam seals are leaking at this point, the grunge on the bottom of the timing belt cover says to me that it was a pre existing condition to my purchase. Did the old glove on the oil filler and had a proud high five, sigh, how pressing is this, if i can wait another couple of weeks (months?) i can better financially afford to do this... but if it needs it now...

Fan motor is not working at all no matter what the speed, everything for climate control lights up otherwise.

Post by **abscate** » 09 Nov 2015, 18:47

The XC models have a twist in the fuel tank that you need yo know about. The axle splits the fuel tank into two, and there is a second fuel pump that moves fuel from one side to the other. The wiring for the gauge is more complicated too. I'm thinking something is up with the fuel delivery between the tanks

Pop up ypthecdipstick. And vent the gas down below the car until you can get to cleaning the PCV, the team, and the engine block

The P2 cars need to be really abused to plug the PCV by the way. Do a couple of early oil changes perhaps with a desludging agent

autoperdu · Post by **autoperdu** » 17 Nov 2015, 18:38

Well I broke down and took it to the dealer to see if there were any existing codes that I wasn't seeing, good news is there were none...though they did want to do a throttle body cleaning (is this different from the cleaning I did with throttle body cleaner?) recommend new motor mounts, front & back and passenger side as well as new blower motor and power unit. Front brake pads and rotors and 4 park bulbs. No mention of PCV hmmm...
Abscate, thanks for the info, it would appear that the tank is reading good again as the fuel gauge went down as normal. What would you recommend as a desludging agent? Should I use so,so synthetic if I am changing earlier (1000, 3000 miles?)

Post by **abscate** » 21 Nov 2015, 04:51

I have had success desludging a VW turbo with a Bell Performance product.

You put it into the crankcase, idle 10 minutes, and then oil change.

SKU to come