GM 2.8, 3.1 & 3.4 Stripped Threads – TIME-SERT 1812CORE
November 10, 2011 12:36 pm Chevrolet, GM Intake, How To Auto Repair, TIME-SERT Kits
DenLorsTools.com Summary: Suggestions on how to properly repair stripped threads for rocker arm bolts in cylinder heads. Tools for repairing rocker arm bolt holes for gm 2.8, 3.1 and 3.4’s. Affected engines in GM vehicles are 2.8, 3.1 and 3.4 Liter V-6 motors. Aluminum cylinder heads used in Chevrolet, Oldsmobile, Buick and Pontiac’s have a common problem with rocker arms coming loose. Misfire codes and very rough running conditions can indicate a fallen rocker arm.
Here’s the common scenario; After replacing the intake gaskets yourself or having a repair shop do the job, the engine starts running horribly! The check engine light comes on and there’s an OBVIOUS misfire. What’s the most common cause? A fallen rocker. ONE bolt holds each rocker. The bolt threads into the aluminum head. There’s a lot of stress on these threads and that’s why they commonly fail. We have an article that covers using a pushrod remover tool that eliminates the need to run these bolts in and out to begin with, which is the best way to avoid wearing these delicate aluminum threads.
The next step is to either replace the cylinder heads or repair the threads. The least expensive repair would be to just repair the threads. The next decision to make is “what repair system to use?” Heli-Coil thread repairs are a popular choice, however any experienced auto technician, if given a choice would go with the TIME SERT brand part number 1812CORE DLT. Need more information? See our article on the difference between Heli coil and Time-Sert before you decide. It’s linked below with the other related pages including the Time Sert thread repair kit.
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Time-Sert 1812CORE Metric 8 x 1.25 mm Thread Repair Kit
Bill :
Date: August 7, 2014 @ 7:46 pm
time sert 1812 core.
Just wondering if this is the proper fix for a stripped out rocker arm bolt. I saw a video by Cadillac Northstar mechanic complaining these inserts only last about 12k miles especially on the head bolts. Is it worth using for a stripped rocker arm bolt hole? Will the repair last?
Bill :
Date: August 7, 2014 @ 7:48 pm
Forgot to mention the engine I will be using this Time Sert kit on is a 99 3.1 engine rocker arm stud hole.
dennisb - Auto Tool Sales :
Date: August 8, 2014 @ 7:11 am
Bill, the only other repair that I’m aware of for the GM rocker arm bolt hole, aluminum thread repair is a Helicoil. The Heli Coil is a thin coil of wire. The Time Sert 1812CORE uses a solid carbon steel insert. We also have the 1812COREBS which is the oversize kit. It is possible that the aluminum in the head that the insert goes into will fail, especially if the insert was not installed properly, but I’ve never heard of either the regular or the oversize carbon steel insert itself failing. Your other option is to replace the expensive cylinder head (with related gaskets, extra labor etc) and have the weaker aluminum threads again like failed to begin with from the factory. As far as the Time Sert NorthStar Head Bolt repair kit, see the following article for more information TIME-SERT Insert VS NorthStar “Stud†Type Repair Kits.