Help Needed - How to Remove SAI Valve In Car

I need to replace my secondary air injection (SAI) shut-off valve while it's in the car (2002 C4S). I've been able to remove the left side bolt, but cannot figure how to reach the bolt on the right without either a special tool or possibly removing the AC compressor just to be able to get a better angle. I've already removed the alternator, unplugged connectors in the way, and have removed the solenoid. Please see photos below to see which bolt I'm having trouble with. I can get a 10mm wrench on it going straight at it, but then can't turn it to the left at all because the valve body is in the way.

I did this last month... It sucked @ss! You need a small wrench a seated creaper to get the right angle and try to be comfortable with your arm stretched and a LOT of patience! After replacing everything under the sun with my emissions controls I still could not pass my states testing. I sent out my DME and had a ROW installed. When the weather turns back to warm I will be retesting the car and then removing all that crap from my trunk! PS good luck with your endevors!

@joe-1972 can you describe the wrench? Was it a regular 10mm stubby, or maybe an offset clawfoot?

Hm. German engineering ... my ash.

UPDATE - I got the thing out. A combination of different wrenches worked. But � now I�m worried about getting that one bolt back in. I�ll definitely be adding thread lock when reinstalling. FYI - it�s pretty crusty with carbon inside it.

Quotes source post: 20379571

Thread lock compounds come in different specs. I've been on the receiving end of the wrong spec used - I think Locite 243 would be the right one to use, but someone please correct me.

I'd use "blue" loctite 242. If something weaker is needed I think the next step down is purple loctite. Definitely don't used red 262 or you will never get it apart.

Sorry for the late response... I am glad you did it! I did use a few different wrenches. But I do not recommend the loctite the new metal gasket is all you need.

I used to formulate Loctite products. If you choose to use a thread locker, 242 is lower strength (and lower viscosity) than 243. Much easier to break loose at a later time.

Quotes source post: 20379571

IMHO,,, NEVER use thread locker on exhaust type fasteners. I know some do recommend that. I've also seen many techs drilling out busted seized exhaust fasteners. My preference is to use 'never seize' . I personally use locktite on very very few fasteners. For many decades now I've used never seize, and don't remember ever having any fastener back out or loosen or need to be drilled out. Use never seize marine or even regular never seize imo. Just make sure to clean/chase/tap (whatever it takes) all threads perfectly so bolt threads in by hand all the way then torque till bolt/stud just starts to stretch. then go back after a few warm cool cycles and re torque. that fastener will never come lose and will be able to get removed when needed. Just a tip I've learned after many many decades of wrenching, take it or leave it...

Quotes source post: 20380923

Hi Joe - I don't quite get what you mean by saying "the new metal gasket is all you need"... what does a gasket have to do with holding a bolt in? I want to use the Loctite on that one bolt that is so difficult to reach as I might not be able to get the correct amount of torque on it.

Quotes source post: 20381225

Thanks for the info, but I'm confused as both products are classified by Loctite as "Medium" strength and "Medium" viscosity. The only noticeable difference mentioned between them is the size of the container. Were you perhaps referring to "222" which is a "Low" strength thread locker?

Quotes source post: 20383786

no sir. 242 was first and developed in the US. 243 came later and was developed in Ireland. 243 strength (and viscosity) was a fair bit higher than 242 but still considered in the �medium� range. 222 is purple and is very low strength. Not sure why but 242 is also light blue while 243 is dark blue. Purple is low, blue is medium, and red is high in terms of strength for threadlockers. Green is wicking (eg 290) but used for retaining applications as well (620, 640, 680).

You know what, given the fact that it was so hard to remove, I would just install the fastener back without any loctite so that the next mechanic (and that might be you) won't invent new four letter words trying to remove it. It's a small thing, no big torque is necessary.

Quotes source post: 20383775

Think I understand your dilemma. Might be best to take the time and move the a/c comp to the side along with anything else needed to correctly apply the proper clamping force torque to all fasteners. Not saying you need room for a torque wrench, just that you need room to be able to slowly feel the torque with your wrists on bolts till it just starts to stretch. Which is usually same as 'German torque specs, "Gooden Tite".' Its a learned skill to be able to feel out the torque when the fastener just starts to stretch into the proper torque vs the bit more it takes to snap the bolt. Or the little bit less torque than needed to allow the incorrect clamping force allowing leaks.... It helps to have room to hold a socket wrench squarely flat on the fastener both by its pivot point and the handle end so as to facilitate your wrists ability to 'feel' the torque applied. Its a little harder to feel torque correctly with just a flat wrench, but also can be done with experience... Make no mistake, the seemingly simple exercise of using the correct torque on all fasteners is the basis/foundation of all assembled mechanical things working correctly for the long run... Its wishful thinking, (even as good as locktite is) , that it is a substitute for the correct fastener clamping torque. If parts are not clamped together correctly they will leak/or improperly clamped pieces will not operate properly, even if bolts stay in place. Bolts need to be stretched/torqued till proper clamping is achieved. If you must fail using the proper torque you'd be better off using a high temp sealer/adhesive on the gasket both sides, but thats still bad mechanical practice. If not done correctly, more than likely you'll be right back to square 1 shortly down the road.... Use to tell quite a few of my service guys when needed,,, 'Never time to do it right always time to do it twice'. jmho

It's an M6 bolt with a 10mm hex head. Maximum torque is 10Nm and I would just torque it to 8Nm and be done. If you roll around cars, you need to be able to torque some M6 nuts to around 8Nm without a torque wrench.