This makes more sense now. The estimate seems a little high, but it is close to the normal range. Timing chain guides can cause this type of noise as well so they are probably right.
As long as them seem like they can be trusted to do the job correctly you might want to have them do it.
You also might want to get a second opinion simply because this is an expensive job. It might be worth it just to be sure.
Monday, September 26th, 2011 AT 10:00 PM