In order to have HARMONI within your engien, yhou must use oils with BETTER RATINGS! DO NOT belive in VISCOSITY RATINGS ALONE! Rely on ILSAC< JASO< ACEA and GL rtatings! Many of todays cars REQURIE SPECIAL ADDITIVES within the oil they use! These PROPER oils have SPOECIFICATION NUMBERS that you must look for! AUDI?VW, e.g. need oil with the 502 and 505 NUMBERS printed on the label! FORD prodcuts do EXCELLENTLY with FORD RATED MOBIL ONE 0W-30 oils! YOUR ISIUE is either NOISY CLOGGED LIFTERS< or a NOISY CLOGGED UP HYDRAULIC TIMING CHAIN TENSIONER! Since you have NOT fully described your car, it is IMPOSSIBLE to give better, more focused advice here! ALl you say here is VAN! WHO MADE IT? anyways, yhou wlil need a FULL MOTOR FLUSHIGN to rid the engien of BAKED IN SLUDGE that resricts OIL FLOW through your engine parts! THEN USE ONLY SYNTHETIC OIL that has YOUR VEHICLE SPECIFICATI*ON NUBMERS printed on the LABEL! Stay away from ALL VALVOLINE PRODCUTS! NO FACTORY anywhere uses it, and it is a WAX REDCUTION OIL! This means that with TIME it turns into HARDENED WAX from which it is DERIVED>! mOST CARS MADE AFTER 2000 requrie full synthetic oil! Otherwise the warranty will be voided out! If you ahve MORE QUESTIONS use my E-mail address email@example.com or CALL ME at 248-818-6747! FEEL FREE! I have repiared cars over the INTERNET all over the WORLD< made by many car makers! The ANSWERS are usually ALL THE SAME anyways. BAD OIL PRESSURE is ALSO caused by POOR OIL CHOICES! It is NOT just the OIL CHANGE INTERVALS but the OIL CHOICES that are plaguing uyou NOW! ALL CARS have an OIL PRESSURE RELIEF VALVE< and if you can IMAGINE TAR forming on this from CHEAP OIL< you wll understand things more clearly! Once TAR is made from CHEAP OIL< you will get LOTS of engine noises! I have seen SUPEB TOYOTA ENGINES fail from CHEAP OIL CHANGES! sAME FO honda! sAME FOR vw/audi AND more! power wash yoru engien WITH gunk orange TO REMOVE all road salt AND CLEAN UP wiring harnesses< BETTERY CABLES AND connectors! fOCUS ON THE space BEHIND THE RADIATOR! mANY TIMES THIS ARES GETS clogged up WITIH LEAVES, SEEDLLINGS, ANIMAL DROIPPINGS AND insects! This causes SLOW DETERIORATION of tghe cooling system and EVENTUALLY oil will get TOO HOT< and makes the hardened SLDUGE that wil eventaully ruin your engine! PLEASE RA|EAD YOUR OWNER's MANUAL and GET SMART! The PROEPR OIL specification numbers for YOUR CAER will be found THERE!<<<YOU CANNOT GO WRONG with MOBIL ONE "0" series oils! They are SUPERB and PREVENT THESE ISSUES from ever happening! The GOOD NEWS is that oNE OIL CHANGE EACH YEAR wil give you MAXIMUM protection, LOWER FRICTION and MORE engien life! PENNZOIL ULTRA EURO gives a 15 year 500k OIL WARRANTY if you can FIND IT! AMSOIL is ANOTHER superb oil for modern car engiens GOOD LUCK andf get that OIL FLUSHIGN DONE! B-G makes a GREAT engien cleaner, and so does AMSOIL! If you have ANY more issues, contact me DIRECTLY at firstname.lastname@example.org!