lgonzalez_1986
dont know **** bout gns
how do you do a leak down test? thanks
leak down test
- Thread starter lgonzalez_1986
- Start date
lgonzalez_1986
dont know **** bout gns
Ok then after that what do I do and what do I look for?
The gauges will show how much leakdown you have. Could be valves, piston rings, ect, ect. One gauge will hold steady pressure the other will show how much leakdown you have. It seems complicated but once you do one cylinder you will fly through the rest. It really gives you a good idea of engine health.
turbofabricator
Well-Known Member
You keepa you digits away from the accessory belt or you coulda loosa a digit or two.
When you plug the shop air into the leak down tester, the engine may rotate FAST, causing fingers to depart your hand if they as anywhere near the belt. Be careful.
As stated above just follow the instructions in the box. Listen to the throttle body for intake valve leaks by the sound of rushing air, then listen to the tail pipe for a leaky exhaust valve, then listen to the valve cover breathers for a leaky ring or head gasket. You will hear the sound of escaping air if it is leaking.
When you plug the shop air into the leak down tester, the engine may rotate FAST, causing fingers to depart your hand if they as anywhere near the belt. Be careful.
As stated above just follow the instructions in the box. Listen to the throttle body for intake valve leaks by the sound of rushing air, then listen to the tail pipe for a leaky exhaust valve, then listen to the valve cover breathers for a leaky ring or head gasket. You will hear the sound of escaping air if it is leaking.
lgonzalez_1986
dont know **** bout gns
where can i get a kit like this?and how much do they go for?
turbofabricator
Well-Known Member
Summit, Jegs or even Harbor Freight has them. Not sure how accurate they are but there's not much to them. I have a Snap-On one, but one from Summit/Jegs would be fine for the money.
lgonzalez_1986
dont know **** bout gns
Thanks you
Not sure what you are trying to find inside your engine, but to get the best results from a leak down test you should loosen all the rockers so none are touching the valves when rotating the engine. They MUST be completely seated for accurate results.
If you suspect a cylinder or 2 does not have good compression, doing a simpler compression test will find that.
With a low compression reading on a cylinder, you may not be able to determine the exact problem, but if it is low due to head gasket, valve or something else, the head has to be removed for repair reguardless, good luck on what your are doing!
If you suspect a cylinder or 2 does not have good compression, doing a simpler compression test will find that.
With a low compression reading on a cylinder, you may not be able to determine the exact problem, but if it is low due to head gasket, valve or something else, the head has to be removed for repair reguardless, good luck on what your are doing!
TurboTdr3.8
Well-Known Member
what readings are ok with turbo engine % leakage , my engine has 7% on all cylinders , is that acceptable ? What does a normal engine have thats been built and broke in have ?
I just finished putting a new set of heads on an 87 that had some cylinders in the 15% range and others in the 39% range. Valves were not seating very good. Compression check said 100 across the board. After heads, 130 and 4-6% leakage. New timing set also while it was all out and apart. Car runs like fresh from the dealer now. Typical rule of thumb is 8% is ok. Anymore and you start to look to where the compression is going.
ek02
Well-Known Member
Not sure what you are trying to find inside your engine, but to get the best results from a leak down test you should loosen all the rockers so none are touching the valves when rotating the engine. They MUST be completely seated for accurate results.
If you suspect a cylinder or 2 does not have good compression, doing a simpler compression test will find that.
With a low compression reading on a cylinder, you may not be able to determine the exact problem, but if it is low due to head gasket, valve or something else, the head has to be removed for repair reguardless, good luck on what your are doing!
X2. A leak down test is not completly acurate unless you loosen the rockers and get each cylinder at TDC. Doing a leak down on a new engine after it is broken in gives a baseline for future tests. Besides testing the valves for leakage, it is a great indication of ring seal as the engine wears.
Well if you have a score in your cylinder lets say below your ring package at TDC a leak down test is not going to catch that. That's why you really need to do both. The fact is they are both a pain in the ass to do in the car that's why I like to do em on an engine stand lol. Hope it checks out ok for ya.
