You get monkeys. This is a saying that we use around our shop whenever we are asked to repair another repair done by unskilled, negligent, unqualified, or inexperienced people. Monkeys. There is another saying that we like to use:
The bitterness of poor quality remains long after the sweetness of low price is forgotten.
We often see people with incorrect spark plugs causing misfires, brake jobs that sound awful, and the occasional shotgun approach to solving a problem (throwing parts at it in the hopes that a wide pattern will hit something). We have been asked to completely re-do engine work due to oil leaks or coolant leaks, and have seen cheap, new (yeah right) engines with cracked blocks. I don’t think I have ever seen what we found today though…
A while back I wrote about the Tacoma 2.7 liter 3rz engine and its balance shafts. As great as this engine is it has some weak points, one of which is the balance shaft assemblies. The other was a cracking exhaust manifold and the tendency to burn exhaust valves without periodic adjustment. What we have been seeing on these heads is that if an exhaust valve burns, it puts a lot more heat into the head and causes them to crack.
The video below is a very, very good tutorial for somebody who doesn’t know how an engine works.
At 1:35 in the video above combustion occurs. What needs to happen for maximum efficiency is that explosion needs to be sealed in the cylinder. That means the valves have to be closed all the way so the combustion doesn’t leak out and all that power of combustion can be used to push the piston down. If a valve is tight, that means the valve isn’t closing all the way because it is being kept open by constant contact with the cam lobe. Exhaust valves tend to burn when they are tight for two reasons: combustion gases are very hot, and they are not making full contact with the cylinder head. The exhaust valves need to transfer their heat to the cylinder head which is kept cool by the engine’s cooling system. They can only do this when they are able to make contact for the length of time the engineers deemed the best when designing the engine.
That being said, we recently had a customer bring his truck to us after he paid peanuts to have his cylinder head replaced. He needed it replaced because of cracks that had formed when one of the exhaust valves burned. Before this truck made it to us, it had a stint at a reputable shop that found all kinds of problems with the work done by the monkeys. He found parts missing, bolts loose, wiring harnesses unsecured and exposed to heat. A lot of stuff that would potentially cause the SEVERE lack of power the customer was experiencing. This other shop tried fixing everything he saw wrong and still it ran like crap.
When we got the Tacoma it barely ran. Compression was decent, fuel quality was fine, spark plugs were good, but the engine vacuum was very low. We went and checked the regular suspects to no avail. Finally we found the problem. The monkeys neglected to follow the procedure for removing the camshafts and had set up a situation where the cam spun inside it’s gear. The step to avoid this takes literally 30 seconds or less. Personally I have never seen this happen and neither had the other shop, which tested our diagnostic capabilities. So, in an attempt to save money by having a cheap unqualified shop do the repair, the customer spent way more than he initially saved, on our diagnostic time, towing fees and the other shop fixing all the problems they saw with the monkey work, as well as having to get a new camshaft installed.
I realize everybody makes mistakes and I am far from perfect. I also realize that beginners to my trade will make mistakes and that is o.k. as long as you make things right and learn from them so it never happens again. What this poor Tacoma went through was just a complete disaster. I have never seen such shoddy unprofessional work, and that is completely unacceptable to me. So think long and hard the next time your cousin tells you he can do it for a third the cost of a reputable shop. You might end up paying three times the shop’s estimate.
