Talk:Quad 4 engine

Comments
The statements of opinion regarding reliabilty have been removed. These appear to be original research, rife with weasel words, and opinion. The citing of specific mileage for failures is unverified original research. The fact that the head and block are different materials is not unusual, since all manufacturers have used dissimilar metals for blocks/heads. How-to information on diagnostics for a blown head gasket is unencyclopedic. Further, specific endorsements of products is not permitted on Wikipedia.

Removed text: Many Quad 4 engines did not see over 120000 mi due to connecting rod issues.The Quad 4 was plagued with blown headgasket issues almost from the introduction of the engine. The problems primarily arose from the fact that the cylinder head was built from aluminum and the block from cast iron, which caused the two parts of the engine to expand unevenly with heat. At approximately 80000 mi the headgasket would begin to leak, and despite numerous redesigned headgaskets, the engine would begin to leak and progress to engine overheating. This could account for a lack of early Quad 4 engines still in operation today. A blown headgasket can be identified by white smoke exiting from the exhaust pipe and an oily residue in the coolant return tank next to the radiator.

Once the headgasket was replaced by a quality aftermarket piece, the engine proved reliable. Victor-Reinz was the OEM gasket supplier, Fel-Pro is the preferred aftermarket gasket maker.

Engines identified by the Twin Cam label currently haven't earned the earlier reputation of the Quad4. The Quad4 had many cases where users would experience a failure of the timing chain around 70000 mi with no history of abuse. Timing failure lead as one of the highest occurring problems with the Quad4. This is due to a poorly spec'ed chain which was longer than the typical chain GM used. The extended length was due to it being a single loop that linked both cams. Most V6's would use two separate and shorter chains to connect to the cams. The failure of the timing chain wasn't seen as a huge problem to the general consumer but a high number of cases are reported daily to aftermarket timing component companies (Call Cloyes for verification).

Coding
Doesn't "W41" refer to a performance package and not the engine itself? Traditionally, GM's W-codes (W30, WS6, etc.) refer to things like Ram Air and not a particular engine. Duncan1800 (talk) 11:17, 20 May 2008 (UTC)