2.0 plenum issue, Can it be removed while in the car? Options

[robkammer]

Hello brain trust! The engine saga continues on our BB. What started in February as an engine reseal, head refresh, and engine compartment repair is still ongoing. The heads needed a full refresh, and close inspection found cracks, that the head expert 'fixed' with Timeserts. Lifter wear pointed to a cam lobe that was half gone. So off the short block went to a very well know Type I and IV engine builder. Wife and I went to Florida and wandered around for a month while this was all taking place. Back to Ohio in March and I started gathering the parts needed for the re-install.
The heads came back looking great, and the short block looked even better, now with fresh bearings, a stock cam and bearings, and a new oil pump.Oh, and we dicovered that I had a 2056, Cool, right?
Got the heads on, all of the tin, wiring and hoses. Put the beast in the car and started the break in process. First 30 miles, then oil change and valve adjust, then 100 more, rinse and repeat. Noticed a pretty significant oil leak coming from the front of the engine. it was the new oil pump, totally unacceptable. The builder came to my shop in hope that the oil cover gasket was the problem. Uh, no.
So out came the motor, back to the builder who is 100 miles away. At the 130 mile mark I also pulled the plugs to see how they were firing. All good, except that three of the Timeserts came out with the plugs, crap.
So while the engine was at the builder I ordered a new set of AMC heads, shipped directly to the builder. Why not, eh?
Get the engine back in with the new heads, start the process again. Got through about 65 miles and the engine is running like crap.
All of the FI bits are working as they should, and all with engine wires are Jeff b's harnesses. The only non functioning bit is the thermo sensor on the side of the plenum.
Plugs looked ok but maybe a bit on the lean side.

Time for a Smoke test! Cool tool for sure, brings back memories of my Lionel trains.

At first glance it looked like the throttle body shaft was leaking, although I had Rocky in Walla Walla rebuild it while the engine was out the second time. Nope, turns out that one of the two unused tubes through the plenum had somehow come loose and is allowing atmosphere into the plenum. I've attached a video.

So after that long intro about my sorrows, the question is: Can I remove the plenum while the engine is in the car? I struggled getting the intake runners onto the plenum the second time while the engine was on the cart, I used the 100 mile old rubber tubes and they may have shrunk. I'll buy new rubbers again, and of course the intake gaskets. But am I delusional that I may be able to get the plenum off in order to repair or replace it without dropping the engine, Again!!??

Any helpful advice will truly be appreciated.

Robbo
 smokin.MOV ( 3.06mb ) Number of downloads: 21

[emerygt350]

Hello brain trust! The engine saga continues on our BB. What started in February as an engine reseal, head refresh, and engine compartment repair is still ongoing. The heads needed a full refresh, and close inspection found cracks, that the head expert 'fixed' with Timeserts. Lifter wear pointed to a cam lobe that was half gone. So off the short block went to a very well know Type I and IV engine builder. Wife and I went to Florida and wandered around for a month while this was all taking place. Back to Ohio in March and I started gathering the parts needed for the re-install.
The heads came back looking great, and the short block looked even better, now with fresh bearings, a stock cam and bearings, and a new oil pump.Oh, and we dicovered that I had a 2056, Cool, right?
Got the heads on, all of the tin, wiring and hoses. Put the beast in the car and started the break in process. First 30 miles, then oil change and valve adjust, then 100 more, rinse and repeat. Noticed a pretty significant oil leak coming from the front of the engine. it was the new oil pump, totally unacceptable. The builder came to my shop in hope that the oil cover gasket was the problem. Uh, no.
So out came the motor, back to the builder who is 100 miles away. At the 130 mile mark I also pulled the plugs to see how they were firing. All good, except that three of the Timeserts came out with the plugs, crap.
So while the engine was at the builder I ordered a new set of AMC heads, shipped directly to the builder. Why not, eh?
Get the engine back in with the new heads, start the process again. Got through about 65 miles and the engine is running like crap.
All of the FI bits are working as they should, and all with engine wires are Jeff b's harnesses. The only non functioning bit is the thermo sensor on the side of the plenum.
Plugs looked ok but maybe a bit on the lean side.

Time for a Smoke test! Cool tool for sure, brings back memories of my Lionel trains.

At first glance it looked like the throttle body shaft was leaking, although I had Rocky in Walla Walla rebuild it while the engine was out the second time. Nope, turns out that one of the two unused tubes through the plenum had somehow come loose and is allowing atmosphere into the plenum. I've attached a video.

So after that long intro about my sorrows, the question is: Can I remove the plenum while the engine is in the car? I struggled getting the intake runners onto the plenum the second time while the engine was on the cart, I used the 100 mile old rubber tubes and they may have shrunk. I'll buy new rubbers again, and of course the intake gaskets. But am I delusional that I may be able to get the plenum off in order to repair or replace it without dropping the engine, Again!!??

Any helpful advice will truly be appreciated.

Robbo
 smokin.MOV ( 3.06mb ) Number of downloads: 21

hold on there... is this djet? If so, vacuum leaks just cause high idle, nothing else.

Let us know and we can guide you through troubleshooting the djet (if that is it).

[robkammer]

I need to fix that leak before going much further. Before pulling the engine out for the oil pump, it was running well, and that plenum was not leaking. It passed the smoke test perfectly. I have a pretty good handle on the D Jet , all components test well, except the Thermotime? sender. Since the car will rarely if ever driven below 40 degrees, I'm not too concerned. If I could find one in working order, I'd buy it anyway.

[JamesM]

Sounds like a bit of an ordeal for sure

Noticed a pretty significant oil leak coming from the front of the engine. it was the new oil pump, totally unacceptable. The builder came to my shop in hope that the oil cover gasket was the problem. Uh, no.

What pump did he use? Almost all available pumps fit like absolute horse (IMG:style_emoticons/default/stromberg.gif) out of the box, will give you leaks and/or low idle oil pressure when warm due to case clearance issues.

All good, except that three of the Timeserts came out with the plugs, crap.
So while the engine was at the builder I ordered a new set of AMC heads, shipped directly to the builder. Why not, eh?

Surprised anyone would even attempt to re-work used type 4 heads these days with the new castings available. Depending on where they come from, out of the box can have issues there as well, usually questionable valvetrain hardware. Best bet is new castings and have the valves/hardware replaced with good stuff by someone that knows what they are doing.

Get the engine back in with the new heads, start the process again. Got through about 65 miles and the engine is running like crap.

Can you elaborate on what it is doing?

All of the FI bits are working as they should, and all with engine wires are Jeff b's harnesses. The only non functioning bit is the thermo sensor on the side of the plenum.
Plugs looked ok but maybe a bit on the lean side.

A non functional thermo sensor on the plenum (assuming we are talking the large switch for the cold start injector) shouldn't be a problem unless its non functional state is shorted to ground, and even then you can just unplug the 5th injector to alleviate that.

Time for a Smoke test! Cool tool for sure, brings back memories of my Lionel trains.

(IMG:style_emoticons/default/biggrin.gif) I find smoke tests are under an utilized and incredibly helpful tool. As you have already seen by identifying the massive leak in your plenum. As already said though that leak is basically just functioning as extra unwanted throttle at this point and wouldnt be impacting to much more than causing high idle. If you are NOT seeing high idle then that indicates someone did something to compensate which COULD be a problem, ie dialing back the timing to control idle speed, etc.

So after that long intro about my sorrows, the question is: Can I remove the plenum while the engine is in the car? I struggled getting the intake runners onto the plenum the second time while the engine was on the cart, I used the 100 mile old rubber tubes and they may have shrunk. I'll buy new rubbers again, and of course the intake gaskets. But am I delusional that I may be able to get the plenum off in order to repair or replace it without dropping the engine, Again!!??

Yes you can pull the entire intake with the engine in the car. Easier if you pull the injectors/rails first as clearance can be tight.

I wouldn't worry much about the hoses if you are not seeing smoke out of them, 100 miles isn't much at all for those and I wouldn't suspect they will give you trouble , but if you want to replace them its not going to hurt.

So far though I don't think anything you mentioned is going to resolve a d-jet car running like crap though. Need more information on the specifics.

Since you have the smoke test machine at the ready, I would highly recommend testing the exhaust system. SUPER common to find leaks here and even guys that install these things every day can struggle to get them to seal. I made it a policy to ALWAYS smoke test exhaust systems on 914s even if the guys had not touched the exhaust because they are that common and often fly under the radar.

My gut is telling me you have some MPS issues and with the car being d-jet AND a 2056 some red flags are raised. Stock d-jet setups only run properly on stock motors without some fiddeling. If you have already confirmed that all components bench tested fine, and that the timing is set properly, I would say next step is getting a widebad AFR meter on it (after confirming no exhaust leaks)

[JamesM]

So while the engine was at the builder I ordered a new set of AMC heads, shipped directly to the builder. Why not, eh?

Another potential red flag.

Do you have the link to the specific heads you ordered?

[robkammer]

Hey Teeners, thanks for all of the replies. A couple of points, I need to fix that plenum leak before I go hunting for anything else. That's just my OCD engineer brain. After staring at it for another hour or so I'm pretty sure I can pull the left side runners away, with the injectors still installed, and have enough room to wiggle the plenum off of the right side runners.
My plan is to braze the through tubes to stop the vacuum issue. I might add a little steel epoxy if my brazing doesn't go too well.
I'll put it back together and start her up! I've inspected and tested just about every bit that is involved. Bench tested three AAR's this afternoon and all are working well.
I bought a China Freight fuel pressure gauge but I'm going to return it. The fitting on the end is an SAE 7/16-20 thread. No one has a barbed fitting that will work.
Any recommendations for an affordable fuel pressure gauge would be great.

RE; The heads, bought them from a source in CA, (AA performance?) the builder took them apart to check spring rates, guide clearances, and valve dimensions. cc'd as well to be sure the comp ratio is where it should be. Even after all of that, I did need to dremel some areas to get the tin to fit.
I'm starting to lose my spark with the older cars. Wifey and I just got back from a 3500 mile road trip to the Rockies in her 'new to us' 24 Macan. Pretty sweet.
Cheers!

[emerygt350]

Just put a plain Jane fuel pressure gauge inline with the cold start valve.

You have still not described what running like crap means. If you have a 2056 and djet, you need to tune the mps. No amount of vacuum leak fixing will change that.

Is the ignition stock?

[robkammer]

Thanks Emory: Yes, stock ignition. Not going anywhere until I fix the vacuum issue. Ran fine before the last engine pull. Everything I've read says not to mess with the MPS. The test I used for the MPS is out of Georges book. It holds vacuum quite well. Really the only things that have changed are fresh heads, better compression, and better valves. And again, it ran well after the first install, other than a bad oil leak at the oil pump. The new pump is a Type I pump.No leaks now.
Going to pull the plenum tomorrow, fix the leak, then back at it in few days. Also need to find that 'plain jane' pressure gauge.

[dax1969]

Noticed a pretty significant oil leak coming from the front of the engine. it was the new oil pump, totally unacceptable. The builder came to my shop in hope that the oil cover gasket was the problem. Uh, no.

What pump did he use? Almost all available pumps fit like absolute horse (IMG:style_emoticons/default/stromberg.gif) out of the box, will give you leaks and/or low idle oil pressure when warm due to case clearance issues.

Don't want to hijack this thread but my new build engine has a leak near the oil pump as well. Shop installed a new "26 mm oilpump" (no further info) and it leaks. Shop assumed it was the oil pump cover so this was flattened and re-installed. Same leak and now they suspect that the gasket moved a bit causing this leak. Car is going back to the shop soon to solve the leak but do you think it could be that wrong or bad oil pump was installed ? which brand/type is best for my 2.0 stock djet ?

Sorry again to interfere with this discussion

thks

[emerygt350]

Thanks Emory: Yes, stock ignition. Not going anywhere until I fix the vacuum issue. Ran fine before the last engine pull. Everything I've read says not to mess with the MPS. The test I used for the MPS is out of Georges book. It holds vacuum quite well. Really the only things that have changed are fresh heads, better compression, and better valves. And again, it ran well after the first install, other than a bad oil leak at the oil pump. The new pump is a Type I pump.No leaks now.
Going to pull the plenum tomorrow, fix the leak, then back at it in few days. Also need to find that 'plain jane' pressure gauge.

A 2056 uses surprisingly more fuel than stock and with the higher compression and unknown quench you will likely need to tune it, or maybe cheat it with some extra resistance in the CHT circuit. Once you get an afr installed you could put 100-200 ohms in that cht line if you notice it is dangerously lean and see how it goes. I wouldn't drive it much without checking the afr and having a CHT gauge installed. Most important is that cht. Hate to trash those new heads.

[Superhawk996]

Noticed a pretty significant oil leak coming from the front of the engine. it was the new oil pump, totally unacceptable. The builder came to my shop in hope that the oil cover gasket was the problem. Uh, no.

What pump did he use? Almost all available pumps fit like absolute horse (IMG:style_emoticons/default/stromberg.gif) out of the box, will give you leaks and/or low idle oil pressure when warm due to case clearance issues.

Don't want to hijack this thread but my new build engine has a leak near the oil pump as well. Shop installed a new "26 mm oilpump" (no further info) and it leaks. Shop assumed it was the oil pump cover so this was flattened and re-installed. Same leak and now they suspect that the gasket moved a bit causing this leak. Car is going back to the shop soon to solve the leak but do you think it could be that wrong or bad oil pump was installed ? which brand/type is best for my 2.0 stock djet ?

Sorry again to interfere with this discussion

thks

Guys - Aftermarket type 1 oil pumps don’t fit type 4 engines. The OD of the type 1 pumps in the aftermarket are mostly grossly undersized, leaving a flimsy paper gastket or RTV trying to hold back oil pressure leaking between the case and the pump body.

Not trying to be short with anyone here but this issue has been known for decades. A quick search here or on TheSamba will confirm the problem as well as the 1/2 (IMG:style_emoticons/default/bootyshake.gif) attempts to address the type 1 shortcomings with o-rings that require the pump to be installed before the case 1/2’s are assembled.

Just to be clear, I’m not frustrated with you guys. I’m frustrated with so called “professional engine builders” that keep using type 1 pumps and don’t take any care to get a pump with properly sized OD to prevent leaks, oil pressure problems, and oil aeration. Yes - Raby uses them. At one point he was also looking into CNC’ing his own pump bodies to ensure proper fit. He may also just be measuring and only using the best fitting pump bodies. You can do that at his price point. The rest of the so called “professional” builders . . . (IMG:style_emoticons/default/barf.gif)

I’ll find you a couple links:

See post #14 for size spec on OD of pumps.
www.914world.com/bbs2/index.php?act=ST&f=2&t=376144

This one pertains to the issues with O-ring pumps
1) The case has to be split to use an O-ring pump
2) Look at where the O-ring is and you’ll see why it can’t prevent external oil leaks and may make them worse. Rather than dumping leaking oil back into the case, the o-ring blocks it and forces it toward the end plate. Will help with pressure loss and aeration though.
3) Need to pay attention to pump port alignment and o-ring position. Likely need to use a spacer to fix. The spacer becomes yet another possible leak path.
4) The o-ring does nothing to keep oil from recirculating between pump outlet and pump inlet.
www.914world.com/bbs2/index.php?act=ST&f=2&t=377358

TheSamba link going back to 2008:
[url] https://www.thesamba.com/vw/forum/viewtopic.php?t=699156[/url]