Jump to content
SAU Community

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


Recommended Posts

I noticed the throttle plate and body were very dirty, so I got a can of Throttle body and Carburettor cleaner, and went to town sprayed the throttle plate and all inside while holding the throttle open. This was on a RB25DET cold car, while the car was OFF. Exactly like this video.

https://www.youtube.com/watch?v=eQpPcdvSBks

When I put it back together start it after waiting about only 15 minutes, it just kept cranking for the first 5-10 seconds or so, couldn't start up at all, then after about 20 seconds of cranking it started to stumble start only a few hundred rpm or so and immediately die. It took a good few minutes to get it to start running even 10% ok. Eventually it started to run without extra throttle but crazy rough. It took about 20 minutes to of idling to smoothen out to a half decent amount, but its still a lot rougher than before.

What concerns me is the engine now just feels rough, even after a day of driving, whereas before it ran smooth. When you shut it off it feels rougher during that second of residual momentum as the engine dies off, as if the internals movement has roughened up (something bent or oil diluted by carb cleaner?)

I didn't realize how fast this Carburettor cleaner builds up into pools of liquid in a corner you cant see. Due to the spray pattern I assumed it was evaporating quickly but it doesn't. You can fill up half a cup with liquid in under 5 seconds of spraying and it doesn't evaporate for days.

Afterwards I had a proper look down the intake and spraying down the throttle plate the way I was it looks like all that liquid would run down to cylinder 3 and 4 (as they are in the middle directly behind the throttle body hole).

During the cleaning I would say I got through about half of a 400g can so cylinder 3 and 4 would literally be flooded with about 100ml of liquid each.

I have a few questions.

1.Does an RB25 starter motor have enough power to bend or damage something internally in a hydro locked situation, or does it have a safety cut off below that amount?. The Battery is brand new and very strong (770 Cranking amps).

2.Assuming various scenarios, how long would it take 100ml of for spray cleaner to run past the intake valves into the combustion chamber and past the rings into the crankcase?

3. Would the fact that the other 4 cylinders weren't flooded mean they were firing right and have enough power to do internal damage from a 0rpm start?

What do you guys think happens when you spray 100ml of combustible fluid down intake for cyl 3 and 4 and try to start it?

Edited by Touring

Have you done simple things like checking plugs, making sure you havent left anything unplugged etc or a line off? Seems like you have just jumped to the worst possible scenario

Yes I did. Went over it about 5 times. There is definitely nothing out of place, I didn't do much to the car besides throttle body clean anyway. I also cleaned out some other bits like the blow off valve with the same carby cleaner.

I'm about to change the engine oil to see if that makes a difference. Whats also strange is the car now has less power after cleaning. I have to hold throttle noticeably further down to maintain the same highway speed compared to before.

My question is, if you were to pour for example 50ml of carby cleaner down the spark plug hole, and sealed it back up, how long would it take to slip past the piston rings into the crank case if it all? Unlike water or gasoline which doesn't mix well with oil and is thick, it should seep past cracks very well.

I know during a leak down test it is normal to have 10% leak in a sealed combustion chamber.

Edited by Touring

I would go with heavily fouled plugs on 3&4 for a start.

Drove about 2 hours at highway speeds, any fouled plugs would have been cleared by now. And besides they would be fouled with carby cleaner which leaves no residuals, not gasoline which has oil in it and leaves residuals.

Drove about 2 hours at highway speeds, any fouled plugs would have been cleared by now. And besides they would be fouled with carby cleaner which leaves no residuals, not gasoline which has oil in it and leaves residuals.

Nuh, uh. All that filthy black shit that you flushed down into 3&4 is what would have cooked onto everything. Could even have a nasty lump of carbon keeping a valve open at the extreme end of possibilities.

FWIW, what you did is NOT how you use carby cleaner to clean a TB. You spray some on and you wipe with a cloth. Bits of cloth wrapped around chopsticks if need be. But you don't just keep spraying and spraying without wondering where everything goes.

  • Like 1

And if you keep shutting people down and saying hydrolock. Then obviously all you want is one person to back you up. Pull your plugs out. Start pulling shit apart. Is blowing black smoke out the back?

Does it smell like fuel in the engine bay with the motor running?

Nuh, uh. All that filthy black shit that you flushed down into 3&4 is what would have cooked onto everything. Could even have a nasty lump of carbon keeping a valve open at the extreme end of possibilities.

FWIW, what you did is NOT how you use carby cleaner to clean a TB. You spray some on and you wipe with a cloth. Bits of cloth wrapped around chopsticks if need be. But you don't just keep spraying and spraying without wondering where everything goes.

So you suggest take out plugs and clean them or replace them? I should mention I changed the spark plugs with new ones of the same sort bcpr6es-11) prior to cleaning the throttle body. Thats why I had the throttle body open. So there is new plugs in there, but I guess brand new plugs aren't immune to being fouled.

Yup what I did was stupid and a huge mistake. I saw mist coming out of the can and didn't realize it was building up so heavily into liquid until I sprayed in a cup.

And if you keep shutting people down and saying hydrolock. Then obviously all you want is one person to back you up. Pull your plugs out. Start pulling shit apart. Is blowing black smoke out the back?

Does it smell like fuel in the engine bay with the motor running?

What? The last thing I want is internal component damage. Don't know why you think I'm shutting people down, I just want to see if anyone can eliminate that hydrolock possibility due to some reason, which would just ease my mind. TPS, AAC valve spark plugs anything else etc is what I want it to be.

No there is no smell or smoke, other than the fact it smells like the car is running overly rich out of the exhaust. It has that typical rich/flooded car hasn't been started a while smell, even after a day.

Edited by Touring

Procedure is to clean intake (with upper engine cleaner) THEN replace plugs.

For the exact reasons people are posting above. The plugs will covered in crap. Also the AAC valve might be clogged, or could be cleaner, either way it will probably have changed so reset the idle. I had to reset the ECU then the idle when I first used upper engine cleaner.

From the mechanics , regardless of what it says on the cans don't spray large amounts of any cleaner down an engines throat without having a few revs up to get it through the system . The last thing I'd do is spray into a cold silent engine .

The drama is any gunge on the inlet system or valves or piston crows can come away and in a slow cranking cold engine can make a mess the plugs won't thank you for .

And yes it's a drama if anything gets caught between the valves and seats and hydraulic lifters pump up .

I'd start with a plug change cheers A.

And to answer thread title question. Yes.

The combustion chamber is around 60 cc. Get close to that in the cylinder and you will have problems.

Just pulled the plugs. They looked ok still next to new, a bit of dark around the base and whitish on the tips. 3 and 4 were definitely a bit darker but didn't look enough to cause fouling. I gave them a spray with the carb cleaner and put them back in and reset ECU. Car runs a bit smoother now but still seems down on power and clunkier running in general. Still smells a bit rich out the exhaust. I wonder if all the uneven carbon that was cleaned out the valves caused them to run rougher. Maybe carbon buildup makes a better seal and unevenly cleaning the valves i.e 3 and 4 got a better clean while the others as still dirty, may mean the engine isn't as balanced.

I am hoping after a few thousand ks things will even out even more.

Definitely pull the plugs out. Inspect. If they look shit get new ones. Make sure you gap them to 0.8mm.
If your plugs look alright. Gap them down and put it back in.

Ive tried 0.8mm in the past and its definitely doesn't feel as strong as 1.1mm down low. It doesn't feel like a misfire anyway, just rough running. I always run the biggest gap I can get away with.

Procedure is to clean intake (with upper engine cleaner) THEN replace plugs.

For the exact reasons people are posting above. The plugs will covered in crap. Also the AAC valve might be clogged, or could be cleaner, either way it will probably have changed so reset the idle. I had to reset the ECU then the idle when I first used upper engine cleaner.

Going to do the AAC valvle as next. Will I need to find a new gasket or can I re use the same one?

From the mechanics , regardless of what it says on the cans don't spray large amounts of any cleaner down an engines throat without having a few revs up to get it through the system . The last thing I'd do is spray into a cold silent engine .

The drama is any gunge on the inlet system or valves or piston crows can come away and in a slow cranking cold engine can make a mess the plugs won't thank you for .

And yes it's a drama if anything gets caught between the valves and seats and hydraulic lifters pump up .

I'd start with a plug change cheers A.

And to answer thread title question. Yes.

The combustion chamber is around 60 cc. Get close to that in the cylinder and you will have problems.

Not good. Assuming it was hydro locked on the cold start, What would pop first, the hydrolic lifters, or the valves themselves?

60cc is at TDC correct? Ok thats not much, but can you tell me how long it would take carby cleaner to run past the rings into the crank?

For example, if you took out a spark plug and filled it to the top with carb cleaner and put the plug back in. Would all the liquid still be there after 15 minutes or would some of it run past the piston into the crank and out of the combustion chamber?

Edited by Touring

Re use the gasket. Put some rtv on it.

And yes I agree with what you said. I like to leave my carbon in the motor. It has sealed my motor over 20 years haha. I don't want to disturb them

It seems you can break stuff with combustible liquid in the combustion chamber.

Sounds like this guy totally bent something by hydolocking the engine. However mine never tried to crank and hydrolock, just would not start

https://www.youtube.com/watch?v=IIROSsb37_s&list=UUvJwC5r81XZfIp7lqAEXIjQ

https://www.youtube.com/watch?v=MKiLczI1rOo

In other words his engine was hydro-locked and 30 minutes later he was able to start it, meaning that some of the liquid ran past the piston rings into the crank?

I gave mine 15 minutes maybe 25 after the spray. I am hoping that was enough to let most of the carb cleaner run past.

Its a long shot, but does anyone have a junk open block that they can spray carb cleaner onto the piston and see how long it takes for the fluid to start dropping past the rings?

Edited by Touring

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.

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...