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LEE 64 Samba Member
Joined: December 13, 2010 Posts: 166 Location: WV
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Posted: Fri Oct 11, 2013 7:40 pm Post subject: compression test in type 4 |
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I did a compression test on my 2000 cc type 4 results follow
cylinder 1 119 psi
cylinder 2 118 psi
cylinder 3 117 .5 psi
cylinder 4 101 psi
is this good ? I don't get the 101 in cylinder 4 is that bad ? |
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kkjellquist Samba Member
Joined: June 04, 2013 Posts: 752 Location: Asheville, NC
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1975 Kombi Samba Member
Joined: August 12, 2007 Posts: 2452 Location: Acton, Ontario, Canada
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Posted: Fri Oct 11, 2013 9:11 pm Post subject: |
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Did you have the following?
Did you adjust the valves?
Was the battery fully charged?
Was the engine warmed up?
Did you remove the air filter and hold the flap open?
Were all 4 plugs removed?
Did you do a wet and dry test?
Did you repeat the process and take the average result?
Did you use equal number of compression strokes for each cylinder? I do 6. _________________ Brett
“He’s decieving you boy! Reach into his pocket and take what he’s got.” Mr. Crabbs.
75 Westy auto
03 Jetta TDI
71 SB
74 Westy
Licensed pilot (single engine land VFR)
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Rust In Pieces: 72 Bug, 73 Bug, 81 Rabbit LS D 2D, 83 Rabbit D 2D, 84 Jetta TD GL, 85 Jetta D, 68 Z28 RS 302, 91 Passat 16v |
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LEE 64 Samba Member
Joined: December 13, 2010 Posts: 166 Location: WV
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Posted: Sat Oct 12, 2013 4:46 am Post subject: ? |
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I don't know what a wet dry test is ? Its FI with hydrolic lifters
I warmed it up first took out all the plugs |
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LEE 64 Samba Member
Joined: December 13, 2010 Posts: 166 Location: WV
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Posted: Sat Oct 12, 2013 4:48 am Post subject: / |
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the battery was fully charged too |
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1975 Kombi Samba Member
Joined: August 12, 2007 Posts: 2452 Location: Acton, Ontario, Canada
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Posted: Sat Oct 12, 2013 6:11 am Post subject: |
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Squirt a teaspoon of oil in each of the cylinders and re check the compression. It lets you know if the extra oil helped seal the rings and gives you an indication that the rings have lost their ability to seal against the cylinder walls. The next test would be a leak down test where compressed air is added to each cylinder while the piston is at the top of it's compression stroke and the time and amount of lost air from the cylinder is monitored. It allows you to hear where the air is escaping and if the valves are bad and how bad. _________________ Brett
“He’s decieving you boy! Reach into his pocket and take what he’s got.” Mr. Crabbs.
75 Westy auto
03 Jetta TDI
71 SB
74 Westy
Licensed pilot (single engine land VFR)
--
Rust In Pieces: 72 Bug, 73 Bug, 81 Rabbit LS D 2D, 83 Rabbit D 2D, 84 Jetta TD GL, 85 Jetta D, 68 Z28 RS 302, 91 Passat 16v |
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Randy in Maine Samba Member
Joined: August 03, 2003 Posts: 34890 Location: The Beach
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50260
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Posted: Sat Oct 12, 2013 11:45 am Post subject: |
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If the engine runs strong, the exhaust sounds the same on all cylinders (use a shop rag to partially clog the tail pipe), and you get about the same rpm drop when you pull each plug wire then the engine is most likely fine. |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sat Oct 12, 2013 5:31 pm Post subject: |
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Yes - you are fine. Write the numbers down and keep them. Compare them over time. |
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bus68us Samba Member
Joined: December 02, 2013 Posts: 18 Location: Phoenix, AZ
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Posted: Sat Feb 24, 2018 11:01 pm Post subject: Re: compression test in type 4 |
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Did a compression check today in my 77' Westy with a 2.0L hydraulic lifters.
I followed Ratwells instructions listed above and averaged 3 readings of each cylinder each cylinder.
Cyl 1: 125
Cyl 2: 122
Cyl 3: 130
Cyl 4: 130
This engine's old, burns a quart of oil in 1000 miles or so and smokes on cold starts. I don't think my rings are bad based on my test. What could be causing oil to burn and smoke when cold?
Also, here's a pic of my plugs. Would you guys agree they're normal?
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williamM Samba Member
Joined: August 07, 2008 Posts: 4333 Location: southwest Arizona
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Posted: Sun Feb 25, 2018 5:18 am Post subject: Re: compression test in type 4 |
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Is it black smoke, and lots of carbon, or blue/white smoke and smells like oil? You may have a problem with cold start??
My GEX motor has 165 # compression if you want to borrow some. _________________ some days I get up and just sit and think. Some days I just sit.
opinion untempered by fact is ignorance.
Don't step in any! |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Sun Feb 25, 2018 9:19 am Post subject: Re: compression test in type 4 |
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Compression rings can still seal well even if the oil rings are weak, could be the rings. Or it may be going through the valve guides. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50260
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Posted: Sun Feb 25, 2018 9:37 am Post subject: Re: compression test in type 4 |
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Sure its not just condensation coming out of your pipe on cold starts? That is absolutely normal.
Using only a quart of oil every thousand miles isn't going to be that easy to diagnose. Those little white specs on the ground electrode of your plugs might be the only sign you will see of oil getting into the cylinders.
I have been able to reduce oil use on some engines by switching to a synthetic oil, I prefer a synthetic for these engines anyway as it can handle heat better than a dino oil. During the summer you could consider just running a 30wt oil, relatively cheap and offers many of the benefits of a synthetic.
Hard to judge plugs these days, but yours may be a heat range too hot. How many miles do you have on them? |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sun Feb 25, 2018 11:05 am Post subject: Re: compression test in type 4 |
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1 quart per 1000 miles is pretty standard on 1970's cars, especially air cooled VW. That is why you check it at each gas fill. These cars can go 800 miles and burn nothing then dump a quart in 200 miles, then burn nothing for the next 500 miles. I'd wager that in their time, more air cooled VW's died from low oil due to owners never checking than any other failure. Today we have parts quality issues. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Sun Feb 25, 2018 11:31 am Post subject: Re: compression test in type 4 |
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SGKent wrote: |
1 quart per 1000 miles is pretty standard on 1970's cars, especially air cooled VW. That is why you check it at each gas fill. These cars can go 800 miles and burn nothing then dump a quart in 200 miles, then burn nothing for the next 500 miles. I'd wager that in their time, more air cooled VW's died from low oil due to owners never checking than any other failure. Today we have parts quality issues. |
I think this is true.
It must also be said....so people do not get confused by reading different accounts elsewhere with type 4 engines used in different vehicles....a lot of teh oil usage also has to do with load and temperature.
Over the years on these and other forums reading what people consider to be normal oil usage...and even some of the anecdotes of manuals over the years...it always struck me as odd that people used so much oil in their buses and considered it normal.
The 411's, 412's and 914's I have worked on and driven (that did not leak) rarely used more 3-4 ounces of oil between 3000 mile oil changes. They were also lighter and geared differently and ran lower temps.
I have driven more than a few buses but only one long term. It used oil at what bus owners consider normal. No smoking...just normal oil usage....about a quart in 1500 miles.
That one being my first and only long term bus ownership...I just thought it was a lower quality build and did not connect the dots until much later.
The other item that contributes greatly to oil usage is frequent short trips with total cool downs in between. If you use your bus....or any acvw mostly in teh "grocery getter" driving style...you will use a lot more oil. All of them use the most oil when starting up from cold.
You will use the least oil if most of your driving is fairly long trips. Ray |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50260
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Posted: Sun Feb 25, 2018 11:51 am Post subject: Re: compression test in type 4 |
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FWIW, I have run my oil a quart over the full mark for the last four decades, which brings the oil level up to about where VW ran it on the Vanagon Waterboxer engines. This gives more oil capacity and more time for the oil to settle in the sump before going through the system again. I suspect it also helps with cooling the oil, but don't know, but running an oil that is thin enough to be routed through the cooler at highway speeds will produce cooler oil that may well not burn off as readily. |
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timvw7476 Samba Member
Joined: June 03, 2013 Posts: 2182 Location: seattle
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Posted: Sun Feb 25, 2018 5:09 pm Post subject: Re: compression test in type 4 |
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Those #s pretty much mean let it run.
Also, it helps to hook up a battery charger while you do it. (testing)
the slower crank speed as you go gets reflected in compression results.
Slower crank, lower result, unless you keep the battery boosted.
Another nasty trick is carbon tends to build in the slow-revving 2.0.
so you get bonus compression numbers as the miles & crud build up.
LubraMoly Fuel Injection Cleaner takes care of that, injected or carbed
type IV engine. |
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bus68us Samba Member
Joined: December 02, 2013 Posts: 18 Location: Phoenix, AZ
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Posted: Sun Feb 25, 2018 10:50 pm Post subject: Re: compression test in type 4 |
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I've definitely noticed a variation with how much oil it burns. For example, on our way out to San Diego (380 miles) it burned a quart (day time, early Oct, temps 90s). On the way home it burned nothing (night time, temp 60's).
It consistently smokes on cold starts and it's bluish/white with an oil smell. It's also had high CO numbers when I emissions tested a few months ago.
Bottom line: We're planning a lengthy road trip to the Northwest this summer and I'm trying to figure out if I should rebuild or put money into other things.
Thanks for all the input guys. I always learn stuff here. |
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udidwht Samba Member
Joined: March 06, 2005 Posts: 3777 Location: Seattle, WA./ HB, Ca./ Shizuoka, Japan
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Posted: Tue Feb 27, 2018 1:34 pm Post subject: Re: compression test in type 4 |
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Well your compression numbers look good. I'd still do a leakdown test and see how the top end pans out. 8-10% is acceptable.
Oil usage could be from worn guides.
As for oil consumption SGKent and Ray are spot on. All things being equal these engines will use oil an average of (1/2qt- 1qt) per 1200-1500 miles or so. Mostly 1/2qt given my drive is... cold start...18 miles to work...park...12hrs later drive back home.
On my last trip (2014) from Seattle to HB, Ca. I used ~2/3 qt (10w-30 VR1) That was with my 2056cc T-4 with new AMC re-worked heads 42x36mm (Headlflow Masters) & 96mm biral AA piston & cylinders and my bottom end that had ~ 50,XXX on it (see sig for full specs). Now have 22,XXX on the top end and ~72,XXX on the bottom.
As for your plugs. Do not use any that are stamped Russia, India or China. In fact, stay away from Bosch plugs period. NGK or nothing. _________________ 1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires |
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Ktk833 Samba Member
Joined: April 04, 2017 Posts: 28 Location: Nairobi, Kenya
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Posted: Thu Mar 03, 2022 8:57 am Post subject: |
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1975 Kombi wrote: |
Did you have the following?
Did you adjust the valves?
Was the battery fully charged?
Was the engine warmed up?
Did you remove the air filter and hold the flap open?
Were all 4 plugs removed?
Did you do a wet and dry test?
Did you repeat the process and take the average result?
Did you use equal number of compression strokes for each cylinder? I do 6. |
Question:
What would you pick of this situation (2.0 liter type 4 engine)?
-Engine was not warm... in fact, has not run in about 2 months.
-Prior to parking, valves had been set presumably right.
-Battery fully charged
-no wet test
Tests results:
Cylinder 1: 55
Cylinder 2: 57
Cylinder 3: 60
Cylinder 4: 62.
All this are initial tests.
Rings are all new.
Also, it was my first time to do a compression test.
What I would like to know, may I far much different results if the engine was warm, if I did a wet test? Are those results way too low even for an engine in the described state?? What else may I do before I undertake subsequent tests?
Thanks. |
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