Purpose:

To show how to repair in-situ a broken stud on the exhaust manifold of a 2001 Volvo V40 1.9T
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Background:

I have a 2001 V40 1.9T with 263,000 km that I have owned since 2002. Two years ago one exhaust manifold stud next to the turbo broke at 230,000 km. The recommended repair procedure included removing the head and replacing it with a new or re-conditioned head. I decide to remove the catalytic convertor, turbo and exhaust manifold to see if there was sufficient room to drill and tap a new stud hole. The following describes the successful in-situ repair.


Repair

First I removed the glycol from the engine and then removed the heat shield from the turbo. The inlet and outlet flexible pipes were removed from the turbo and all opening blanked.

I then removed the catalytic convertor from the car. The flexible exhaust pipe had recently been changed so the lower nuts removed easily from the studs. While under the car you also need to remove the large bolt that support the catalytic convertor. Moving topsides I removed the three bolts securing the convertor to the turbo exhaust discharge. I disconnect the oxygen sensor at the electrical plug and lifted convertor from car.

I then removed both turbo coolant pipes followed by the turbo oil supply pipe. The turbo oil drain pipe was left attached to the turbo during both removal and reinstallation. The Torx fasteners on the oil return pipe are impossible to remove and install. The four fasteners that hold the turbo to the manifold need to be removed to remove turbo with oil drain pipe connected.

The next part of the repair involved removing the exhaust manifold without breaking any more studs. Once the manifold is removed be sure to put clean rags in each exhaust hole. I did break two more studs but it occurred at the nut thus I had a length of stud to attach vice grips. I did get those studs removed eventually. A couple of hits with a large hammer, install a washer on stud then vice grips and finally work then stud back and forth until it starts to work itself free. This is a tricky part of job thus if you have never removed seized studs before then your are probably going to break studs at head and then will need to replace head. The exhaust manifold studs nearest to the turbo broke with the original stud factured at the head as can be seen in the bottom left hand corner of the second picture.

At this point I only had one stud to drill and tap thus I continued with in-situ repair. The drilling involves building a hardwood jig with a nylon guide for the drill bits as shown in the third picture. This guide helps to keep drill at right angles as you drill out old stud. You should start with 1/8” drill and work up in four increments until you get to the correct size for the tapping operation. You should use new drills for harden steel and drill slowly using cutting fluid. If you break a drill at this point deep in the hole you will be replacing the head. Use the other holes for a depth guide. If you get thru phase without breaking a drill celebrate.

Now for the tapping phase which you will need a regular tap and a bottoming tap. Start with the regular tap and go slowly. If you have never tapped before then this is not the job for learning. Remove tap regularly to clean and lubricate. You break the tap in the hole and you will be replacing the head. Use the bottoming tap to cut the final threads at bottom of hole. If you get thru this phase without breaking tap then celebrate large. The difficult part of job is behind you.

Now the reassembly part begins. I ordered three replacement studs and nuts, exhaust manifold gasket, both coolant pipes and seals, oil pipe seals, convertor gaskets. I cleaned the exhaust surface on head and manifold, installed three new studs and new gasket and then installed manifold and torqued it correctly.

Then I installed turbo complete with oil drain pipe. A bit tricky but it will go. I then installed the bolts that hold turbo to manifold. The oil supply pipe was connected. The old pipes were badly corroded so new coolant pipes were installed.

The catalytic convertor was installed with new gaskets and the oxygen sensor plug installed. The inlet and outlet pipes were connected to the turbo and the engine filled with glycol.

The repair took three evening to complete and cost $150 in parts. The car has operated two years and 30,000 km.

Summary

If your 2001 V40 1.9T breaks a manifold stud it can be repaired in-situ. It is not an easy repair because to the drilling and tapping operations in a confined area but the reward is significant if your are successful.

 

Wow, nicely done! You. Saved yourself some serious $. It's hard to imagine having to replace a whole engine due to one siezed bolt. Thanks for posting. I hope that I never have to undertake this job.

 

Hi Guys,

Well - I survived replacing the PCV Oil Trap / Breather Box system - new hoses and all. Now I have a damaged #4 Cylinder Exhaust Manifold Gasket. Probably due to a leaking Camshaft Oil seal, recently replaced with no new oil leaks.

I would be grateful for tips on not screwing up re:
** Breaking studs, seized nuts - what to spray on them to loosen ??
** How to get the exhaust manifold off - been told I may have to pry it off and don't want to damage the ?block?
** Can I just loosen the nuts and pull it back enough to put on the new gaskets - or do I have to remove other parts like the ? turbo drain tubes?

You can tell I am a newbie, but I did the above two jobs so I have a little experience.

Many thanks in advance for your help.

Tom