Comp and leakdown #s
#1
Burning Brakes
Thread Starter
Comp and leakdown #s
Going to be jumping back into the 993 pool here soon and looking for the right car. Heart set on white and found a car and have done the ppi with a reputable shop. For a 95 with @85k miles how do these numbers look?
*
COMPRESSION TEST
(1)*** 130
(2)*** 135
(3)*** 140
(4)*** 140
(5)*** 140
(6)*** 135
*LEAK DOWN TEST******************************************************************** *************************************
(1)*** 9%
(2)*** 8%
(3)*** 6%
(4)*** 4%
(5)*** 5%
(6). 8%
Reading other threads seems
Like for those that have reported numbers the compression figures look low and the leakdowns are in the acceptable range. Other than a weep at the timing chain covers everything else looked fine. Thoughts?
*
COMPRESSION TEST
(1)*** 130
(2)*** 135
(3)*** 140
(4)*** 140
(5)*** 140
(6)*** 135
*LEAK DOWN TEST******************************************************************** *************************************
(1)*** 9%
(2)*** 8%
(3)*** 6%
(4)*** 4%
(5)*** 5%
(6). 8%
Reading other threads seems
Like for those that have reported numbers the compression figures look low and the leakdowns are in the acceptable range. Other than a weep at the timing chain covers everything else looked fine. Thoughts?
#2
Banned
Join Date: May 2008
Location: Arlington Heights, IL
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Bill, to me, those leakdown numbers look high. And they have a large gap from highest (9%) to lowest (4%). Has the car ever had a top-end done? May need one soon. Factor that into your price and value proposition.
#5
Race Car
Out of curiosity why would you pass on that car? If the buyer negotiated the top end (or a large portion of it) in the buy price he could get the repairs done and have a car that starts from a fresh rebuild. As the OP said all other items (except weeping timing chain covers) are fine.
OP - In my opinion if you like this car and you know exactly what you are paying for and what needs to be fixed go for it. If the price when you are done is close to or is what you would have paid for a car that didn't need a top end, why not pursue this one?
Just another opinion. Best of luck in your search. It's really all about the price you pay vs what the car needs. I see it as No HTwo O does
Mike
OP - In my opinion if you like this car and you know exactly what you are paying for and what needs to be fixed go for it. If the price when you are done is close to or is what you would have paid for a car that didn't need a top end, why not pursue this one?
Just another opinion. Best of luck in your search. It's really all about the price you pay vs what the car needs. I see it as No HTwo O does
Mike
#6
Drifting
Unlikely the seller is going to drop the price $5-$10k don't you think?
Out of curiosity why would you pass on that car? If the buyer negotiated the top end (or a large portion of it) in the buy price he could get the repairs done and have a car that starts from a fresh rebuild. As the OP said all other items (except weeping timing chain covers) are fine.
OP - In my opinion if you like this car and you know exactly what you are paying for and what needs to be fixed go for it. If the price when you are done is close to or is what you would have paid for a car that didn't need a top end, why not pursue this one?
Just another opinion. Best of luck in your search. It's really all about the price you pay vs what the car needs. I see it as No HTwo O does
Mike
OP - In my opinion if you like this car and you know exactly what you are paying for and what needs to be fixed go for it. If the price when you are done is close to or is what you would have paid for a car that didn't need a top end, why not pursue this one?
Just another opinion. Best of luck in your search. It's really all about the price you pay vs what the car needs. I see it as No HTwo O does
Mike
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#8
Rennlist Member
May be o.k. for the shop but not me...leakdown has too much variance and compression numbers, while fairly close, are on the low side. Either pass or factor in the necessary engine work...along with a clutch (which is a no-brainer with the engine out).
#10
Race Car
Mike
#11
The compression numbers is a bit low, but that could be due to a weak battery or throttle not being opened when cranking.
But what's wrong with the leakdown number? It's a variance of less than 5%. Only a brand new engine would have less than 5%. This is a 85K mile engine. From what I've seen, many people would be very happy with the leakdown.
But what's wrong with the leakdown number? It's a variance of less than 5%. Only a brand new engine would have less than 5%. This is a 85K mile engine. From what I've seen, many people would be very happy with the leakdown.
#12
Race Director
The compression numbers is a bit low, but that could be due to a weak battery or throttle not being opened when cranking.
But what's wrong with the leakdown number? It's a variance of less than 5%. Only a brand new engine would have less than 5%. This is a 85K mile engine. From what I've seen, many people would be very happy with the leakdown.
But what's wrong with the leakdown number? It's a variance of less than 5%. Only a brand new engine would have less than 5%. This is a 85K mile engine. From what I've seen, many people would be very happy with the leakdown.
A brand new engine with seated rings should leak down about 1%. A good condition 85k mile motor could leak down as little as 1% to about 7%. Once you get into the 8%+ range, you start to get into valve guide replacement territory.
To say only a brand new motor leaks down less than 5% is not accurate.
However, 8% leakdown doesn't mean that you can't drive it for another 30k miles without much issue. And thats the precise reason that most sellers won't want to reduce the price substantially, because to them, the "car runs fine".
#13
Guest
Posts: n/a
+1
Disagree.
A brand new engine with seated rings should leak down about 1%. A good condition 85k mile motor could leak down as little as 1% to about 7%. Once you get into the 8%+ range, you start to get into valve guide replacement territory.
To say only a brand new motor leaks down less than 5% is not accurate.
However, 8% leakdown doesn't mean that you can't drive it for another 30k miles without much issue. And thats the precise reason that most sellers won't want to reduce the price substantially, because to them, the "car runs fine".
A brand new engine with seated rings should leak down about 1%. A good condition 85k mile motor could leak down as little as 1% to about 7%. Once you get into the 8%+ range, you start to get into valve guide replacement territory.
To say only a brand new motor leaks down less than 5% is not accurate.
However, 8% leakdown doesn't mean that you can't drive it for another 30k miles without much issue. And thats the precise reason that most sellers won't want to reduce the price substantially, because to them, the "car runs fine".
#14
Disagree.
A brand new engine with seated rings should leak down about 1%. A good condition 85k mile motor could leak down as little as 1% to about 7%. Once you get into the 8%+ range, you start to get into valve guide replacement territory.
To say only a brand new motor leaks down less than 5% is not accurate.
However, 8% leakdown doesn't mean that you can't drive it for another 30k miles without much issue. And thats the precise reason that most sellers won't want to reduce the price substantially, because to them, the "car runs fine".
A brand new engine with seated rings should leak down about 1%. A good condition 85k mile motor could leak down as little as 1% to about 7%. Once you get into the 8%+ range, you start to get into valve guide replacement territory.
To say only a brand new motor leaks down less than 5% is not accurate.
However, 8% leakdown doesn't mean that you can't drive it for another 30k miles without much issue. And thats the precise reason that most sellers won't want to reduce the price substantially, because to them, the "car runs fine".
Also, leakdown doesn't indicate valve guide problem. The seal on the valve against the cyl head. The valve guide problem is at the stem end near the rocker. Unless you have bad enough of a valve guide problem that the stem begins to rock and damage the valve sealing surface at the cylinder head. By then, the car would smoke like crazy!!
#15
Race Director
7% I can believe, and it's a good number. But I'd like to see pics of a leakdown picture of an 85K mile with 1% leakdown!!!
Also, leakdown doesn't indicate valve guide problem. The seal on the valve against the cyl head. The valve guide problem is at the stem end near the rocker. Unless you have bad enough of a valve guide problem that the stem begins to rock and damage the valve sealing surface at the cylinder head. By then, the car would smoke like crazy!!
Also, leakdown doesn't indicate valve guide problem. The seal on the valve against the cyl head. The valve guide problem is at the stem end near the rocker. Unless you have bad enough of a valve guide problem that the stem begins to rock and damage the valve sealing surface at the cylinder head. By then, the car would smoke like crazy!!
As for the valve guides, you've nailed it exactly. The guide wears allowing excessive valve stem play, which beats up the valve seats and the valves.
Keep in mind that you will always lose some cylinder pressure through the rings, and natural wear on the valve and seat from mileage, and then some stem movement due to guide wear, and it adds up to 8%+ leakdown.
Given the cats most people use, the car probably won't smoke too badly until you get into the 15% range, if I had to guess. At that point, the oil consumption would be your first clue to a problem.