question is what is a sure sign the you overboosted your engine and it is damaged. For example will you see unstable idle, low vacuum, smoking exhaust? In other words what are the symthoms. And can a 4g63 handle occasional brief overboost aka a few counts of knock with immediate letting off the throttle? Just curious since i will be leaving my tuned boost level and driving lightly during the cold weather.

 

If you overboosted without damaging anything then there won't be any signs.

How is your boost controlled? Ideally it should be adjusted for weather.

 

I have Mbc, and what are the signs if any were to be shown? Are the ones i stated correct?

 

If you lift and warp the head you could start pressurizing the cooling system. This would cause the overflow bottle overflow when driving hard. This is what happened to me when I blew the headgasket.

If it's an MBC then just turn it down a turn or something. No reason risking your engine for something so simple.

 

Ok yikes my head was just fully rebuilt deffenetly dont want to be doing that again, what about thes rods, pistons? How will you know when they let go besides one through the oilpan.

 

Can't answer that, never had it happen to me.

 

Anyone else ever experience symptoms after overboosting their engine?

 

It went a little faster?

Either your tune is safe or it isn't. If it's safe, overboosting won't hurt anything and you'll merely go "OH ****" and get out of it. If it's not safe, things are going go boom.

Back in the day, I was tuned on pump gas, 24psi. One particularly cold night my boost controller must have had some moisture in it that froze it shut, and the VIII turbo ended up spinning out 32psi. Car took it like a champ and nothing ever came of it.

If your tune is junk and you spun out a few extra pounds, it could lift the head, it could knock bad enough to cause physical damage to plugs, valves, ringlands, etc, you get the idea.

Other side is that it could be completely unrelated.

 

Ok thanks for the info, before when i had the bad head i would get random knock, an now with the rebuilt head and a conserative tune at 23 pounds i want to make sure occasional overboost wont blow anything bc i overboosted breifly twice since my tune but it was done in warm weather compared to now. Just want to make sure im not breaking anything, i dont drive like an idiot so im confident enough to not over boost it again