Problems with a VW 16V

J

jimbbski

New member
I've been working on getting this ITA Scriocco 16V ready for a drivers school in July. As part of that process I attended a HPDE event last Saturday. The car handled quite well, no bad habits and the car would rotate nicely when I lifted the throttle on corner entry for turns that did not require braking. The problem is the motor spun a rod bearing and took out the block. I don't have it apart yet but when there is almost no water in the radiator and water & oil in the pan you know you have a problem.

This engine was the original and had no special prep done to it as I had planned on replacing it once I sorted the chassis out and got my license.
What I'm looking for is some suggestions on what mods I should do to the oil pan and the oil system in general. I do have a oil cooler mounted in front of the radiator but the sandwitch plate I'm using has a thermostat in it. I think that may be limiting the flow of oil to the cooler and that's why I saw oil temps of 240 deg. on a day where the temps never got above the low 70's. I also have a Moroso Accusump plumbed to the oil filter mount where the oil exits the oil filter and enters the engine. The oil pan is stock but with a couple of baffels added to keep oil near the oil pump pickup and a windage tray/oil pan gasket. .

During my time on track Saturday I saw good oil pressure when I looked at the guage but I only looked while on the straights. There is one long left turn that may have resulted in the oil pump sucking air and the engine loosing oil pressure despite the Accusump. I was told this by another VW racer at the track. He lost an engine there so he knows what he's talking about.

What I plan on doing to the replacement engine is getting a new sandwitch plate that will direct more oil to the oil cooler, add a warning light that will let me know if the oil pressure drops below say 20-25 lbs.
I am also thinking about an aftermarket oil pan or further modifying the stock one. Any other suggestions?
 
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The stock cooler is fine if you run only full synthetic oil. The accusump should cover any air/oil loss for about 20 seconds. I have not used a accusump on any VW engines, just BMW and Chevys. The Stock ABA tray/baffle seems to work fine ,we never get any oil pressure drop in our IT cars.
I use only a warning light, with two bulbs,
Al of my new builds, use the ABA baffle and delete the tray/trap doors.
My(12yrold) Rocco has a trap door lower pan and the scrapper tray. Stock cooler, synthetic oil(mobil one or Rotella Blue) It has about 30,000 race miles. I swap the rod bearings every Feb, and lap the valves.
I suspect that your engine had worn rod bearings or was running on dyno oil. Water in the oil is a head gasket issue, the rod bearing failure is a result of water inthe oil,IMHO. Not an oilling problem.
 
The 16v oil pickup baffles coupled with the diesel windage tray is pretty effective for oil control on these motors. A 'trap door' box around the pickup is probably better. I agree that you should consider dropping the thermostat on the sandwich adapter. An accusump is not really needed in all but the most extreme situations - though I don't use one and hold pressure through the carosel at Road America.

Don't overlook the water system as a route to lower oil and engine temps. Good ducting that only allows air entering the front of the car to pass through the heat exchangers can make a big difference. Also if there is an H2O thermostat, run a cooler temp one.
 
Get rid of the oil radiator and put in the original oil/water inter-cooler sandwich @the oil filter hsg-I promise it works better than the heavier/more vulnerable oil radiator.
Get the factory windage-tray/oilpan gasket setup.
Factory oilpump (not Brazilian, Chinese, or any other aftermarket mfg; a good used factory pump is OK 2nd choice)
Absolutely get a ~30psi warning sender and a light you can't miss.
Keep the oil just to the upper mark of the stick but never overfilled.
Run the factory/steel 5qt pan.
Run good synthetic (ie: Mobil 1) oil 10w-30
Run std brg clearances.
People will tell you alu pans, trap door pickups. accusumps, etc ad nauseum, but these readily available parts work 100% in IT.
And you should have an oil press gague w/rapid response (i.e: mechanical/AN3 lines) in your field of vision.
 
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Thanks for the responces so far.

I do have the VW combo windage tray/pan gasket. I do have a -3 line to a mechanical oil pressure guage and two mechanical oil temps guages, one in the pan and one in the sandwitch plate. I did this to see how well the oil cooler did it's job. I have also sealed the area in front of the radiator to force any air entering to go through the cooler and the radiator.

i don't like the oil-to-water OEM cooler. It may work well but it's a PITA with all the coolant hoses etc. to deal with. On a street car I can see it but on a race car I prefer oil-to-air or a remote oil-to-water cooler.

The motor is locked up so I know something broke in the bottom end and took out a cylinder wall. I haven't pulled the head but I will do so tomorrow. I hope that it's OK as I have another stock short block I can use as a replacement for this one. I will check the bearings on it before I install it.

Could you have one bad bearing and still have good oil pressure on these engines? I would see up to 90 psi on start up cold and 50-55 psi once the engine warmed up enough to come down to a normal idle. Hot the pressure dropped to a more expected 20-30 psi at idle. Pressure climbed with rpms, maintaining a ratio of about 8-10 psi per 1000 rpms.

The only warning I got was the engines reluctance to rev as quickly in the second of two sessions I got to drive. There was a ticking noise at idle but I thought it was the lifters as they make a bit of noise and have always done so. It was during this second session that the engine died when I lifted off the gas to brake for a turn. I then saw a cloud of blue smoke behind me. As I slowed I tried to restart the engine but it would not crank.

Despite some oil on the exterior of the engine I have yet to find where it came from. No hole in the block that I can see, no broken oil line, etc.
 
Synthetic oil?
The bad bearing would make some noise and have lower oil pressure. The problem is that the VW has so much oil volume that it will still show pretty good oil pressure @ any RPM over idle. If the idle # is less than 3#, with noise, you may have an problem. I dont use a gauge, just a light, for this very reason.
If the head drops a valve, or a piece , the rod bearings gets beat up from smashing crap into the head/piston.
When lots(2?) of oldtimers( sorry Phil) say to keep the stock cooler and loose the front mount cooler. Why would you do anything else.?IMHO.
The oil temps read very high on a VW.
Unhook the oil temp gauge, use a synthetic oil,freshen the rod bearings every year, use the 6 Pc thrust bearing. The engine will last a long time if you keep the water cool enough . IMHO. MM
 
Further update: I pulled the head last night and found #2 cylinder head gasket blown out. The bottom end rotates freely. Apparently when the gasket went the engine died and all the oil in the accusump was forced into the engine as well as the coolant, which was also under pressure. This may have filled up the oil pan to the point that the motor was hydrolocked. This may be why when I attempted to start the engine in the padock it would not turn over.

Until I pull the engine out of the car I can't say if the short block is damaged in any way but I will not reuse it intill it is checked out. I will use the known good short block I got out of a parts car to get the car running again.

What I will do is take the head apart and have it milled flat, there is a small bit of damage at the site of the blown gasket. How much can you take off safely? I want to take off as little as possible knowing IT rules limit how much you can anyway. I will also dissasemble the short block and have that decked, again taking as little as possible to get it flat.

With fresh bearings it shoud be good for the rest of this year? Would it be worth while having the cylinders lightly honed and installing new rings? Or since I'm not boring the cylinders to just go with what is there.
 
If you tear down a motor, even if the bores are in good shape, you should always hone for a re-ring.

I suspect that there may be more damage, however.
 
The short block i would have used was not the one in the car but one out of a parts car that was in good running order when I purchased it.

Anyway upon further reflection I have decided to just install a complete engine that I purchased a few years ago that was freshly rebuilt but saw only some test miles in another ITA Scriocco race car. I can have the car up and running sooner and cheaper going this way. I just need to pull the pan and head to verify condition of the internals.

I can put together this new/use short block and my old head together at a later date.
 
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