Valve cover bolt

[hsmith]

Greetings,

I am planning on getting my valves adjusted around the first of the month - in the meantime I thought I would tighten up the valve cover bolts just a little bit because I notice some hint of oil coming out. I didn't put very much pressure & the bolt twisted. I'm wondering what I will have to go through to get this fixed? I don't want to let someone work on it until I get an idea on what should be done. Have a good evening - thanks.

Hugh Sr
1984 190d 2.2 132,453

[jkubica]

Originally Posted by hsmith

Greetings,

I am planning on getting my valves adjusted around the first of the month - in the meantime I thought I would tighten up the valve cover bolts just a little bit because I notice some hint of oil coming out. I didn't put very much pressure & the bolt twisted. I'm wondering what I will have to go through to get this fixed? I don't want to let someone work on it until I get an idea on what should be done. Have a good evening - thanks.

Hugh Sr
1984 190d 2.2 132,453

Hi

I don't know the 190d since I have a 300td, but I guess you mean the bolt broke off? Or that it's turning and not doing anything. Is the head cast iron? Are you planning to do the repair yourself?

With a little more information it will easier to advise.

Joseph

[Diesel911]

I also have a 300D but on mine there are studs going into the Cylinder Head and Nuts that hold down the Valve Cover.

If the Nut is turning around the stud and the Stud is not moving there are several Threads/posts on how do deal with them.

If it is only the nut that is turning in general you wedge something under the nut and pry up while you turn the nut off in hopes of catching some good threads and getting the nut off.

Grabbing the nut with a vice grips and pulling up on it and trying to back it out.

If you have a Dremel tool and small grinding bits you could grind the nut in two.

If there is enought room for it to fit there is also a tool; a Nut Splitter that will crack the nut on one side.

After that you replace what ever is damaged.

[Diesel911]

Originally Posted by Diesel911

I also have a 300D but on mine there are studs going into the Cylinder Head and Nuts that hold down the Valve Cover.

If the Nut is turning around the stud and the Stud is not moving there are several Threads/posts on how do deal with them.

If it is only the nut that is turning in general you wedge something under the nut and pry up while you turn the nut off in hopes of catching some good threads and getting the nut off.

Grabbing the nut with a vice grips and pulling up on it and trying to back it out.

If you have a Dremel tool and small grinding bits you could grind the nut in two.

If there is enought room for it to fit there is also a tool; a Nut Splitter that will crack the nut on one side.

After that you replace what ever is damaged.

This is a pic of a big Nut Splitter; they make small ones to.

[hsmith]

Thank ya'll,

Well, the bolt broke. I can't tell how far down from the top of the bolt it broke without taking off the valve cover. What's so odd is how easy it broke. When that one broke I thought - o no, I better tighten up the other rear bolt to make sure no oil leaks out, but that one broke just as easy. The 1984 190d has an aluminum head. If it broke even with the head what would be involved to repair it? Appreciate your help.

Hugh Sr

[Cr from Texas]

I suspect the PO or his mechanic tried to stop a leak the same way you did and damaged the bolts. They've got to come out. The cover has to come off and hope there is enough left to get a grip on to remove (probably not). If not, the remaining bolt has to be drilled and extracted. I like to use left hand bits and this often will remove the bolt. If not, it leaves a hole into which you insert an extractor. Doing a steel bolt out of aluminum is doable but not a recommended learning job. You can easily have the bit slip and drill into the aluminum. Then you'll end up using a helicoil or something similar.

To avoid this, I never grip the end of the rachet handle when working with aluminum. Hold your hand over the rachet assembly to avoid applying too much torque or use a torque wrench. The first one I broke (in 1962) was because I read the inch-pound value as foot-pounds.

[charmalu]

Left handed drill bits are not real common. I tried Sears, Home Depot etc... finally found a set at Harbor Freight for $7.00. I know made in China, best low quality one`s I could find.

Charlie

[Cr from Texas]

Originally Posted by charmalu

Left handed drill bits are not real common. I tried Sears, Home Depot etc... finally found a set at Harbor Freight for $7.00. I know made in China, best low quality one`s I could find.

Charlie

The first ones I had came with an extractor set. I think I got the replacements at Harbor Freight also.

Don't forget to put the drill in reverse!

[JMan300sd]

I've done the same thing. I over torqued the valve cover bolts and the stud and cylinder block threads were busted. It's a real PITA to fix. But, trust me.....you will never over torque them again

[leathermang]

Left hand drills...
Look in the phonebook for Bolts... there are specialty places which have all this kind of stuff in big towns... or in farming communities where tractors are worked on regularly..

[hsmith]

Thanks for the advice. By the way, what is the torque on valve cover bolts (it is a bolt because the ratchet fit over the top, I think 10mm)? Think Phil might have the bolts, or is this a dealer part?

Hugh Sr

[Diesel911]

Originally Posted by Cr from Texas

I suspect the PO or his mechanic tried to stop a leak the same way you did and damaged the bolts. They've got to come out. The cover has to come off and hope there is enough left to get a grip on to remove (probably not). If not, the remaining bolt has to be drilled and extracted. I like to use left hand bits and this often will remove the bolt. If not, it leaves a hole into which you insert an extractor. Doing a steel bolt out of aluminum is doable but not a recommended learning job. You can easily have the bit slip and drill into the aluminum. Then you'll end up using a helicoil or something similar.

To avoid this, I never grip the end of the rachet handle when working with aluminum. Hold your hand over the rachet assembly to avoid applying too much torque or use a torque wrench. The first one I broke (in 1962) was because I read the inch-pound value as foot-pounds.

With good luck he will have enough sticking out to unscrew what is left.

What I have found that is extremely important when using Ezee-Outs is drilling the hole in the center of the Bolt/Stud and using the correct sized drill to match the Ezee-Out you are using. (Center Punch the hole before drilling and if you have thinner drill bits; drill a piolet hole with the thinner drill first.)
As stated by the time you drill the hole with a Left Handed Drill Bit the torque and heat created by the drilling will often loosen it and even spin it out.
Also the Ezee-outs that have a spiral or screw like appearance can expand a hard to turn out bolt.
(I have not used the newer self drilling types so I do not know how well they work)
Here is a pic of some spiral and some square Ezee-Outs.

[Cr from Texas]

Originally Posted by Diesel911

With good luck he will have enough sticking out to unscrew what is left.

What I have found that is extremely important when using Ezee-Outs is drilling the hole in the center of the Bolt/Stud and using the correct sized drill to match the Ezee-Out you are using. (Center Punch the hole before drilling and if you have thinner drill bits; drill a piolet hole with the thinner drill first.)
As stated by the time you drill the hole with a Left Handed Drill Bit the torque and heat created by the drilling will often loosen it and even spin it out.
Also the Ezee-outs that have a spiral or screw like appearance can expand a hard to turn out bolt.
(I have not used the newer self drilling types so I do not know how well they work)
Here is a pic of some spiral and some square Ezee-Outs.

Looks like the spirals are left handed thread. It might be easier to keep that design centered?

[2.5Turbo]

Also, the 190D 2.2 uses the 601 engine which has hydraulic valve lifters and does not require valve adjustments like the 61x engines.

[sixto]

I thought some early 601s needed valve adjustments.

If there is some shank above the head surface but vice grips don't do it, something like this -

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96335

or this -

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94640

might do it.

The bolt takes a 10mm wrench but it's otherwise known as a 6mm bolt. You should be able to find a suitable metric bolt at any hardware or auto parts store. Bring a good one to match.

The torque is so inconsequentially low that you should use a screwdriver type tool rather than a wrench. If it's leaking, you need a new gasket, not tighter bolts.

Sixto
87 300D