Say you have a Volkswagen enginewith a combination of symptomssuch as hard starting, an intermittentno-start, loading up when cold andmisfiring when cold. Many tech-nicians would probably agree that

certain basic items such as fuel pressure,coolant sensor signal, etc., should be checkedon this 1997 Eurovan. But I wonder howmany would suspect a bad oil pump! In Ren-ton, Washington, MOTOR reader Nidal She-hadeh learned the hard way that a bad oilpump could cause these conditions as well as abundle of trouble codes.

People say that experience is the bestteacher. But as this episode proves again, un-less you’ve experienced the “experience,” ex-perience isn’t much help. Furthermore, She-hadeh’s battle with this Eurovan reinforces

the importance of stopping, taking a deepbreath and doing some homework beforedriving yourself crazy over a problem. Andalthough all kinds of information sources areavailable to us today, Shehadeh’s experiencereminds us that the old practice of maintain-ing good working relationships with local cardealers is still an invaluable resource for us.Here’s what happened.

According to Shehadeh, the basic com-plaint on this ’97 Eurovan VR6 was that itran rough when it was cold but fine when itwarmed up. The computer had stored mis-fire codes P0300, P0301 and P0304. Hesuspected the root of the problem might bein the fuel system but dutiful ly testedeverything he thought might be relevant,from fuel pressure to the ignition system toall the critical sensor signals. He also testedthe charging system, thinking that electri-cal noise from a failing alternator might bethe troublemaker. However, nothing She-hadeh tested was marginally bad or defi-nitely faulty. He began to wonder if theECM was failing.

At kind of an impasse, he telephoned thetech hotline service the shop uses. As itturned out, he had already tested literallyevery item the hotline technician recom-mended. So Shehadeh decided that for bet-ter or worse, it was finally time to try somethings, to take some educated guesses. Hetried replacing the coil pack assembly(waste-spark ignition) and then a new airflowsensor, but the cold-running symptoms per-sisted. He also cleared the misfire troublecodes one night before leaving the shop. Thefollowing morning the Eurovan misfiredwhen cold—per the usual—and thencoughed up a new trouble code, P0306.

Now when he revved the engine, it wouldbegin misfiring when cold and would even-tually load up and stall out. When he tried torestart it, the engine cranked very quickly asif it had lost compression. Almost pre-

Cracking a difficult diagnosis often requires the use

of every available resource. But in the end, your

most valuable tool may be simple perseverance.

DanMarinucci

Foreign Service

10 July 2003

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: Nid

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Cold oil pressure on this ’97 Eurovan is greater than 225 psi. MOTOR

reader Nidal Shehadeh got a tip that excessive oil pressure could becausing the van’s driveability problems. The pressure pumped up thelifters and held the valves open when the engine was cold.

continued on page 12

dictably, the plugs would load upand become fuel-soaked if he con-tinued cranking it.

Not wanting to leave any of thebasics to chance, Shehadeh tried totest cranking compression. Then an-other weird thing happened: Nomatter how quickly he worked,cranking compression was normalby the time he got the gauge intothe spark plug hole and cranked theengine again.

The Right Advice At the Right TimeCoincidentally, Shehadeh was alsochasing down a trans-related VWproblem on a different vehicle thatprompted him to contact the localVW service manager. Because theman readily solved that problem forhim, Shehadeh decided to go two-for-two by asking about the strangesymptoms on the Eurovan. The ser-vice manager surprised him by rec-ommending he check the vehicle’soil pressure. Since about 1995, heexplained, he had seen several cas-es of faulty oil pumps causing ex-tremely high oil pressure. The ex-cess ive oi l pressure, in turn,pumped up the lifters and held thevalves open.

When he returned to the shop,Shehadeh checked oil pressure andsaw yet another strange symptom:Cold oil pressure could be as low as20 psi, but the moment he revvedthe engine, oil pressure skyrocketedto 200 to 250 psi! If, like me, you’rewondering why the excessive pres-sure didn’t blow the oil filter wideopen, note that Volkswagen wentback to cartridge-style oil filters inthe later 1990s.

This Eurovan runs fine now thatShehadeh replaced the oil pump.Cold oil pressure doesn’t exceed 60to 80 psi, and the pressure risesslowly and smoothly when the en-gine is revved.

The kicker to this story is thatShehadeh soon got to apply his newexperience. Soon after solving theEurovan’s problem, he took in a1997 VW Passat VR6 with the samesymptoms and codes P0300, P0302,

P0305 and P0306. Oil pressure onthis engine was shooting up into therange of 150 to 200 psi when cold.No surprises this t ime—and nobrain-wracking, either!—because anew oil pump fixed it right away.Good work, sir! Hurrah for persis-tence and checking the basics.

As an update of our two-partstory on Mitsubishi t iming beltservice (May and June 2003), read-

er Brad Petersen responded withthis tip: If you don’t have a camalignment tool such as the CAM-LOK handy, you can s l ide an8x1.25mm flanged bolt in betweenthe cam sprockets. “Adjust” thisnut and bolt to a snug fit , thencarefully secure it with string orwire so it can’t fall into the engine.Then remove the t iming be l t .Thanks for your input, Brad.

Foreign Service

12 July 2003

A few moments after the initial reading, the oil pressure on the Eurovan hadcome down to 100 psi, but it’s still much higher than the normal cold pressureof 60 to 80 psi Shehadeh measured after replacing the oil pump.

The new oil pump on the right solved all the Eurovan’s problems. Soon afterthis episode, Shehadeh encountered the very same condition on a ’97 Passat!