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Can You Hydrolock Break An Rb With Half A Can Of Carby Cleaner Down The Intake?


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Ok today I changed the engine oil with 10w 50 penrite synthetic and its much much better in terms of smoothness and vibrations. Not back to its pre touched self, but I'm hoping the rest of the vibrations will even out, although I am doubtful. Its possible that when I sprayed the crap out of the blow off valve with carb cleaner a lot of it got sucked into the turbo and somehow made it into the engine oil diluting it and making it more watery. Same with running past the piston rings.

I have to say I have been feeling pretty gut wrenched about not doing the job right and in a hurry, but there was so much gunk and i just kept spraying and spraying.

Whats funny is the car now has a much more pronounced typical RB25 or 26 sound, with a lot more backfires under off low throttle conditions and rawness to it coming out the exhaust, whereas before it was more like a patrol engine. Smooth and wispy. Probably 15 years of carbon build up gave the metal parts a nice cushion and now there is more direct metal to metal contact. It almost sounds like a WRX relatively speaking.

Even though the idle smoothened out, when I slowly rise the rpm in neutral and hold it a certain level, say 2000 it still vibrates a lot more than I am used to, then smoothens out a bit between 2000 and 3000rpm, then gets a shaky again at 3300, then smoothens out at the higher rpms. Hmm.

Whats funny is the rich smell is still there but its getting less and less. It leads me to believe there was some pool of carby cleaner still left over somewhere, maybe in the intake, blow of valve or within the turbo system. I say that because I also sprayed the crap out of the blow off valve.

To go back to your question of 2 posts ago......if you have a cylinder full of liquid and you crank it over until it compression locks, then you will not damage the valves or the lifters. You cannot. Think about it. What you can do is bend conrods, damage crank and rod bearings (and probably gudgeons) and lift the head if the head bolts/studs are not up to it and/ore damage the head gasket. In extreme cases you can split a bore.

To answer your original question and what has been repeated in your last post.....who the hell knows if the stuff would still be sitting in the cylinder after 15 minutes? If there was more than 60cc of liquid in there then you will have definitely locked it. If there was enough force applied to bend a rod, then you are currently running with one or more bent rods, which will not be pleasant.

At this point you may as well spray a can of Subie's upper cylinder cleaner into it (following the instructions of course and see if you can clean it out more thoroughly and see what progresses from there.

You mean because the valves sit on the inside of the combustion chamber and when they close they rest flush against the metal upwards meaning the cannot be pushed up any further? Yea that makes sense, but it could certainly score them or scratch them making a less than perfect seating?

Im not so sure if I locked it at any stage... The engine didn't try to turn over and lock up at any stage. Just crank without starting and took a few good minutes to get going.

I guess I can always easily check if I bent a rod buy simply checking the heights of the corresponding pistons through the spark plug holes and seeing if they match up in height.

Ive never heard of subies cylinder cleaner but I'll look into it. Is that like seafoam? No chance of doing any damage by following instructions I take it? I have heard of seafoam causing damage even when instructions are followed

Edited by Touring

gap your plugs down to 0.8mm

1,1mm is about 43 thousandths of an inch

0.8mm is about 31 thou - still a massive gap

And don't forget the gap just grows as the km go by.

  • Like 1

Ive never heard of subies cylinder cleaner but I'll look into it. Is that like seafoam? No chance of doing any damage by following instructions I take it? I have heard of seafoam causing damage even when instructions are followed

Subie being Subaru. Their upper engine celeaner being the original and the best.

  • 2 weeks later...

Can I ask what brand of cleaner did you use.

I have tested probably every brand of carby/brake cleaner over the years and bmw brake cleaner was the only product that left no residue. Recently I ran out and tried the bendix brake cleaner and it was better than most. The problem with all the other brands is they must have water or some other substance that does not evaporate. Circuit board cleaner is also a great product to use but you have to buy a quality brand and it's expensive.

Your cardinal sin was,,,as has been pointed out is never spray anything into an engine while it's not running. Actually never spray anything into an older engine.Clean your bits off the car mate. 20 years of carbon and slight sludge build up is a good thing for hydraulic lifters and the like.

Hope it all comes good.

Neil.

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