606 head bolt stretch

[96E300D]

Hey Guys,
I've read most of the threads about bolt stretching and what I've come up with is that there was a 3.5mm allowable difference. However more recent publications are using 2mm as a reference. Anyone know for sure? My 96 E300 uses the 102mm and 115mm bolts. A couple of other things on the subject, should the threads on the block be cleaned with a tap and re-lubed before assembly? Also, is $50 a avg. price to have the injectors tested?
Thanks,
Matt

[96E300D]

Nevermind about the injectors, I've found a link that tests them for $3 each, although that means shipping from CA to NY and back.

[dieseldiehard]

Originally Posted by 96E300D

Nevermind about the injectors, I've found a link that tests them for $3 each, although that means shipping from CA to NY and back.

Ship them to the Bosch local authorized injector repair and calibration place, Pacific Fuel Injection in So. San Francisco. around $10 ea. I would worry about a place that says they calibrate them for $3 each.

http://www.bayarea02.com/features/pfister-interview/

[dieseldiehard]

Originally Posted by 96E300D

Hey Guys,
I've read most of the threads about bolt stretching and what I've come up with is that there was a 3.5mm allowable difference. However more recent publications are using 2mm as a reference. Anyone know for sure? My 96 E300 uses the 102mm and 115mm bolts. A couple of other things on the subject, should the threads on the block be cleaned with a tap and re-lubed before assembly? Also, is $50 a avg. price to have the injectors tested?
Thanks,
Matt

use a long thin brush to clean the threads, not a tap! you don't want to remove metal from the threads.
I blow the recess in the block dry with compressed air then apply lube to the threads on the bolts. I use a brass wire brush on the bolts first if the the threads are dirty. The FSM calls for applying oil to the threads I like to use antisieze or molycoat. I always use new bolts, was never fond of risking a broken stretch bolt.

[engatwork]

I am going to have to respectfully disagree with you dieseldiehard. I have always used a bottom tap to chase the threads followed by blowing them out and then using new bolts. In my opinion, the correct size tap on good threads should not remove any metal - just clean it up.

[blueranger]

i just did a 300e head gasket..
go to auto zone and buy there 9 dollar metric tape
set... and chase the threads...

you wont believe the gunk...

and if this is the first rebuild forget about the head bolts..
they will work fine... you could measure and make sure there not to
long but just reuse them and dont worry..

also dot worry about your injectors... the 300e is notorious
for the head gasket... that is your real problem... send your head
off and have the valve guides and seals replaceds... and have it
cleaned and made flat....

the biggest problem you will encounter is the front plastic timing guide..
only 10 bucks but if you break the old one your work doubles...

think about your distributor and spark plug wires... but remember there
200 bucks... i found a bad spark plug wire and went to the junk yard
and got one for free...

[blueranger]

i did my own m104 1988 300e but i paid to have my
96 300te done... because of the duel overhead cam..
its ashame that your having to do this to a 96...after
2 years of struggle on the 96 we finally bought an engine.

[sixto]

96 300TE?

Sixto
87 300SDL

[Brian Carlton]

Originally Posted by dieseldiehard

Ship them to the Bosch local authorized injector repair and calibration place, Pacific Fuel Injection in So. San Francisco. around $10 ea. I would worry about a place that says they calibrate them for $3 each.

Reid, it's one of our members (buyabsellonebay) who does it himself. It's posted on the tools for rent thread. He did mine and found one of them to be NG. Jim sent me two and one of them was perfect. No need to spend any more money than $3.00.

[dieseldiehard]

Originally Posted by Brian Carlton

Reid, it's one of our members (buyabsellonebay) who does it himself. It's posted on the tools for rent thread. He did mine and found one of them to be NG. Jim sent me two and one of them was perfect. No need to spend any more money than $3.00.

Oh, THAT is great nerws Brian. I wasn't aware that we had a member testing injectors, in that case go for it. But does he calibrate them and match them too?

[dieseldiehard]

Originally Posted by engatwork

I am going to have to respectfully disagree with you dieseldiehard. I have always used a bottom tap to chase the threads followed by blowing them out and then using new bolts. In my opinion, the correct size tap on good threads should not remove any metal - just clean it up.

OK I concede, engatwork!
experienced mechanics are excepted and can use a tap wherever they see the need. I was sorta addressing the avg shirtsleeve weekend mechanic (like myself!) at least I would know better than remove metal unless the threads were flattened and a bolt was dragging. Remember the thing we are talking about initially is an engine block, an E300D if someone cross threaded a tap accidentally then we are talking some deep helicoil or something to repair it and that isn't something I would want in my block, thank you!

So I'll restate it that if you have the right tap (bottoming tap) and find the threads are gunked badly or something, it's not a bad idea to run a tap thru them CAREFULLY.

I saw what a tap used incorrectly can do to open up threads to the point they don't grab properly on a head (exhaust studs) as some fellow must have used a plug tap I suppose.

I recently cleaned the holes in my 603 block using a thin bottle type brush with short stiff bristles, the right brush in not easy to find but it will remove gunk from inside threads in a short order. I used WD40 and wore a full face mask as the stuff flies out when you twist the brush as you remove it. I figure it would have added about half an hour to the job if I had to run a tap thru 13 holes that deep.

[f4iman78]

I have done a few head gasket jobs. I usually clean with brake clean and brush. Clean/lube bolts with oil (also apply a little bit of oil where the head of the bolt contact area to the engine head). I have never seen/used antiseize on head bolts ( I don't know if its good/bad to do, just never have heard about it). The main reason of oiling the threads, among other reasons, is to properly torque with lowest friction as possible. Reusing head bolts is fine as long as its within specs (that why the engineers who designed the cars have given you these specs).I have never used a tap to clean the threads myself, but as long as you use the correct size, probably wouldn't hurt. Although, in my experience, I have had taps break (without excessive pressure being used) while cleaning threads on other parts of vehicles. Wouldn't that suck getting a broken tap out of a head.Hopefully some of this information helps. Good luck.

[Brian Carlton]

Originally Posted by dieseldiehard

Oh, THAT is great nerws Brian. I wasn't aware that we had a member testing injectors, in that case go for it. But does he calibrate them and match them too?

He does calibrate and match them. He can't fix a nozzle that won't perform and does not have an available supply of German nozzles, so, if one won't play, then it's time to scour a junkyard or contact someone who can.

But, for $3.00 per injector, you can get the same results as a Bosch shop if repairs are not required.

[blueranger]

the trick is to use the absolute matching tap...
i cant remember what it is but take a bolt with you...
go to the autozone bolt sale area.. screw your bolt in there nut..
then go and get the cheap tap set... and it will be something like
m24 or something like that...

and if the tap absolutely matches all you pull out is grease... no
metal...

[96E300D]

Thanks a million for all the tips guys, will let you know what happens. All the head bolts were within 2mm so I'll go with them and CAREFULLY clean out the threads with a tap. Mark, at the machine shop, said the guides for the intakes were o.k., however the exhaust guides were out of tolerance. Regarding the injectors, the car was running great other than overheating on mountain roads, so I'm guessing the injectors will be fine maybe just cleaned up a bit.
Matt