Pyrometer Thermocouple Installation Pictorial - PeachParts Mercedes-Benz Forum

bgkast · #1 10-16-2006, 02:19 AM

Before you begin make sure you have your thermocouple, a new turbo gasket set, and Brian Carlton’s EGR block off plate.

1) Disconnect negative battery cable. Actually do this…I did not and it cause some excitement later on.
2) Remove air filter and any other stuff that will be in the way
3) Remove turbo oil line EGR, and exhaust downpipe
4) Remove the 6 bolts that hold the manifolds on (one is hidden behind where the EGR was) and the turbo support bracket (you will see it under the turbine housing)

bgkast · #2 10-16-2006, 02:24 AM

5) Pull the turbo and manifold back off of head
6) Remove turbo snaking it past the oil supply line (it would be much easier if the supply line was removed, but you need to drain the oil for that)
7) Bring manifold inside and set on some cardboard so your wife won’t kill you.
8) Remove bolts that hold turbo to exhaust manifold
9) Realize that bolts are stuck, spray with penetrating oil and have a beer

Thanks to the wife for snapping that last picture...although I think she may have been taking it to show the divorce lawyer.

More to come!

PanzerSD · #3 10-16-2006, 02:32 AM

I'll mention that the turbo support bracket is a MAJOR PITA to get at and remove...

and how exactly did you manage to get the exhaust manifold off without removing the intake manifold???

bgkast · #4 10-16-2006, 02:44 AM

The support bolt wasn't too bad, I just had to crawl under the car to get at it.

To remove only the exhaust manifold I simply only pulled on the exhaust manifold. I did later remove the intake manifold as well to replace the manifold gasket.

thorsen · #5 10-16-2006, 07:53 AM

Glad to see I'm not the only person that wears the PepBoys overalls!

Shorebilly · #6 10-16-2006, 03:52 PM

Howdy,

I will assume that this is an incomplete photo essay......was wondering exactly where you intend to mount your Exhaust Temperature Gage/Pyrometer's Thermocouple???

I intend to also install a Pyrometer for my Exhaust Temp...however I had not considered dismounting the Turbo.....I was/am going to simply purchase a new Exhaust Header Pipe......mark the existing one at the point where there is sufficient clearance in car.....as close to the Turbo as possible.....remove the existing pipe, truck both parts down to my welder dude....then have my "Superwelder" weld a spigot onto the new header pipe, in location where marked on old pipe, drilling a hole, of course......then installing the new header pipe, with thermocouple installed.....and then wiring the pyrometer up.

I intend to watch this thread, perhaps I will find a better location to mount mine, but....so far it looks like a whole lot more work.....

Note: I became divorced quite a few years ago.....one of the little things that I learned was....never put your wire wheels in the dishwasher......you're doing a good job with the wife so far...lol

SB

bgkast · #7 10-16-2006, 05:22 PM

Yep, it is incomplete. I am mounting the thermocuople the location shown in the picture below (thanks to ForcedInduction for the pic. Look for more steps this evening or tomorrow.

bgkast · #8 10-18-2006, 02:16 AM

10) Use heat and penetrating oil to remove stuck bolts. Be sure to use a high quality open end wrench to avoid rounding off the nuts.
11) Remove Turbo from Manifold
12) Drill hole for thermocouple. My thermocouple required a ¼ inch NPT thread, which required a 7/16 inch hole. I had my friend who runs a machine shop drill the hole for me.
13) Use the proper tap to thread the hole. The tap requires a lot of down force in addition to twist to get started. Be sure to keep the tap well oiled while cutting the threads.

bgkast · #9 10-18-2006, 02:16 AM

14) Every few turns of the tap remove it and check to see if the pyrometer fitting will start threading into the hole. The threads are tapered to create a seal and because we are dealing with a fairly thin hole you do not want to go too far and cause the hole to be too large. This is also a good time to clean off the tap.
15) When you can thread the thermocouple fitting in a turn or two by hand you are set. Clean the metal filings out of the manifold and use some emery cloth to take the burrs off of the hole.

bgkast · #10 10-18-2006, 02:19 AM

16) Install the pyrometer fitting using high temp anti-seize.
17) When the fitting is tight it should barely protrude into the manifold. Wipe off any extra anti-seize.
18) Install the EGR block off kit as per included instructions and re-install the turbo using new gaskets and anti-seize on the bolts.

More to come…

Shorebilly · #11 10-18-2006, 07:16 AM

G'mornin',

Nice job.......have enjoyed your photo essay so far.....

SB

bgkast · #12 10-19-2006, 11:30 PM

19) Clean gasket mating surfaces on manifolds using a wire brush, emery paper (if necessary) and a paper towel.
20) Clean gasket mating surface on head and install gasket
21) Put turbo and manifolds back in engine bay and connect thermocouple to fitting.
22) Install manifolds. It may help to loosen the turbo support brace to get the manifold into place.
23) Tighten all bolts and nuts, reinstall oil lines and downpipe.
24) Realize that you forgot to double check that the oil return line was aligned. MAKE SURE YOU CHECK THE OIL RETURN LINE BEFORE YOU INSTALL THE TURBO AND MANIFOLD!!!

bgkast · #13 10-19-2006, 11:33 PM

25) Try to remove oil return line to fix mistake
26) Realize that the EGR runner prevents the return line from being installed with the turbo in place.
27) Curse long retired Mercedes engineer and the federal government.
28) Remove manifold again to fix oil return line.
29) Reinstall manifold again.
30) Install air cleaner check all connections, start car and check for exhaust and oil leaks.
31) Go for a test drive and enjoy your new gauge.

Unfortunately my pyrometer fogged up when I turned on the headlights. Grr! Then on the test drive my speedometer cable started howling.

More projects...

Wallknight · #14 10-19-2006, 11:53 PM

Ok, looks good. But I have to ask the dumb question: What's the point of knowing exhaust temp?
Sorry in advance for asking...

bgkast · #15 10-20-2006, 12:00 AM

When the exhaust gets too hot bad things can start to happened. Not really an issue when the car is stock, but I plan to turn up the fuel and add an intercooler soon.

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